Adequate hematological, renal, metabolic and hepatic function within 7-10 days prior to randomization Adequate hepatic and renal function Adequate organ function as demonstrated by hematological, renal, hepatic laboratory assessments; Adequate renal, bone marrow, hepatic, pulmonary, and cardiac function Must have adequate hepatic, renal, cardiac and hematopoietic function Has adequate bone marrow, renal and hepatic function based upon laboratory tests as follows: Hepatic function as follows: Participant has adequate bone marrow, renal, and hepatic function. Insufficient hepatic and renal function. Adequate hepatic function as evidenced by: The following criteria for evidence of adequate hepatic function performed within 2 weeks prior to study entry must be met: Participants have adequate bone marrow, renal, hepatic and coagulation function. Adequate hepatic function Adequate hepatic function Adequate hepatic, renal, and bone marrow function: Subjects with documented hepatic metastases involving >50% of the hepatic parenchyma. Adequate hepatic function: Patients must have adequate hepatic function as evidenced by: Hepatic: Adequate liver function is defined as: Patients must have adequate bone marrow, hepatic and renal function as defined below: Adequate bone marrow function, hepatic function, and renal function Participant has adequate bone marrow, renal and hepatic function. The following criteria for evidence of adequate hepatic function performed within 28 days prior to randomization must be met: Adequate hepatic function Active or severe hepatic or renal disease. Patient with adequate bone marrow reserve, hepatic and renal functions Adequate hepatic function within 28 days prior to study registration defined as meeting all of the following criteria: Adequate hepatic function. Adequate hepatic function, as follows: Has adequate hematopoietic, coagulation, renal and hepatic function. Subject must remain eligible for continued treatment with tazemetostat according to the eligibility and treatment criteria from the antecedent study. Adequate bone marrow, renal, hepatic, and metabolic function (assessed ? 7 days before inclusion in the study): Adequate renal and hepatic function Hepatic and renal function Adequate organ function: Patients should have adequate hepatic, renal, cardiac and pulmonary function to undergo reduced intensity HCT based upon local institutional guidelines, or at a minimum meet requirements noted in eligibility checklist Appendix A-VIII_1. However, significant hepatic and pulmonary dysfunction, if secondary to underlying LCH disease activity, will not exclude patients from protocol enrollment and should be discussed with the National PI Coordinator and the Coordinating Principal Investigator. Adequate renal and hepatic function: Adequate renal and hepatic function, per laboratory reference range at screening Subjects must have adequate hepatic, renal, and bone marrow function. There are no specific minimum criteria for enrollment; this will at the discretion of the treating physician, as any patient who would be considered for standard of care treatment with these drugs may be considered for this trial Adequate hepatic function Demonstrate adequate hematological, renal, hepatic, and coagulation function; Adequate hepatic profile. Adequate hepatic profile: Adequate hematological, hepatic and renal function prior to first dose Adequate renal, hepatic, pulmonary and cardiac function defined as: Must have adequate bone marrow, renal, and hepatic function (For the sub-study, the subject must have adequate bone marrow and renal function and have mild-to-moderate hepatic impairment) Renal function and Hepatic function Adequate bone marrow (BM), renal, hepatic and metabolic function. Adequate renal and hepatic function as defined: Subject has evidence of hepatic dysfunction defined as: Adequate organ function, including renal and hepatic function based on the last assessment performed within the Screening Period Patients enrolled in the Dose Finding Portion of the Study: Impaired hepatic or renal function, inadequate bone marrow reserve or organ function, Cardiac dysfunction Adequate renal, hepatic, cardiac, and pulmonary function as evidenced by: Adequate bone marrow, renal, hepatic, pulmonary, and cardiac function Adequate hepatic function Hepatic function, as follows: iC9-CAR19 CELL INFUSION: Demonstrate adequate renal and hepatic function; all screening labs to be obtained within 24 hrs prior to cell infusion Participants have adequate bone marrow, renal, hepatic and coagulation function. DONOR: Cardiac, renal, pulmonary, and hepatic function within normal limits Adequate hepatic function as defined as follows: Adequate hepatic function defined as: Adequate hematological, hepatic and renal function Adequate hepatic and renal functions as defined by: Impaired hepatic or renal function as demonstrated by any of the following laboratory values: INR > 1.5 or other evidence of impaired hepatic synthesis function. The patient has adequate hepatic function per protocol Patients with history of hepatic dysfunction or hepatic disease and abnormal liver function tests defined aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline (Alk) phosphatase (Phos), and or total bilirubin greater than 2.5 times the upper limit of normal; patients who have a history of hepatic dysfunction or hepatic disease and normal liver function tests will be eligible to participate Documented hepatic insufficiency or renal failure Adequate hepatic and renal functions as defined by: Hepatic function: Adequate hepatic function, with bilirubin < 1.5 x the ULN, and AST and ALT < 2.5 x ULN Adequate renal and hepatic function: Adequate hepatic and renal function Bone marrow, hepatic, and renal function as follows: Hepatic function, renal function, bone marrow function in defined lab-value-ranges Hepatic Function: Have adequate hepatic function as defined by the following criteria: Subject has adequate bone marrow, renal, and hepatic function. Adequate bone marrow, renal, hepatic, pulmonary, and cardiac function defined as: Must have adequate hepatic and kidney function. Adequate hematological, renal, hepatic and coagulation function is required. Hepatic Adequate renal and hepatic function: Adequate hematopoietic capacity, hepatic and renal function Adequate hepatic function: Has adequate hepatic function, defined as: The following criteria for evidence of adequate hepatic function performed within 4 weeks prior to study entry must be met: Adequate bone marrow reserves, hepatic function, and renal function Adequate hematological, hepatic, and renal function: History of hepatic disease or significant hepatic dysfunction Must have adequate bone marrow and renal/hepatic function at the screening and baseline visits, defined as: Adequate hepatic function performed within 4 weeks prior to study entry must be met: Hepatic metastases Adequate hepatic function as documented by serum bilirubin< 1.5 mg/dl and SGOT and SGPT 1.5 or less x upper limit of normal. Adequate bone marrow, hepatic, and renal function Adequate bone marrow, hepatic, and renal function, as specified in the protocol Participants must have adequate bone marrow, hepatic and renal function Adequate bone marrow, hepatic, and renal function, as specified in the protocol Adequate bone marrow (BM), renal, hepatic and metabolic function; Participant has adequate bone marrow, renal, and hepatic function. Renal and hepatic function values exceeding 2 times the upper normal value Has protocol-defined adequate renal, hepatic and cardiac status Adequate bone marrow, hepatic, and renal function Adequate renal and hepatic function: Adequate bone marrow, renal and hepatic function: Adequate hepatic function within 48 hours prior to induction chemotherapy Adequate hepatic function Adequate hepatic function (>= 1.5 x upper limit of normal [ULN]; patient’s with Gilbert’s disease are not excluded) Adequate hematopoietic, renal, and hepatic functions defined as: Have adequate hepatic function Adequate hepatic function, with bilirubin < 1.5 x the ULN, and AST and ALT < 2.5 x ULN. Patients with both hepatic and renal dysfunction will also be excluded Adequate bone marrow, kidney, and hepatic function (no laboratory value > 2 times the normal limit) Adequate hepatic and renal function (these must be WNL or verified by study chair to be related to conditions not interfering with normal health status) Hepatic Function: Adequate baseline renal and hepatic function Inadequate hepatic function Adequate haematological, hepatic and renal functions defined by the protocol Have adequate hepatic function. Adequate hepatic and renal function defined as: Adequate hepatic function The patient has adequate baseline organ function, including cardiac, renal, and hepatic function: The patient has adequate baseline organ function, including cardiac, renal, and hepatic function: Has protocol-defined adequate cardiac, renal and hepatic function Adequate renal and hepatic function defined as: Subjects who have adequate hematological, renal, hepatic and respiratory functions defined. Participant must have adequate bone marrow, renal, and hepatic function. Adequate hepatic, and renal function Adequate Blood, renal and hepatic function, as determined within 28 days from registration: Adequate renal and hepatic function Adequate hematological, hepatic and renal function (renal function considered adequate as per protocol definition) Adequate hepatic and renal function Hepatic function: The following criteria for evidence of adequate hepatic function performed within 4 weeks prior to randomization must be met: Patients must have adequate bone marrow, renal, hepatic, and neurologic functions Adequate hematological, renal, hepatic, and coagulation laboratory assessments Subject has adequate bone marrow, renal, hepatic and coagulation function. Adequate renal, hepatic and pancreatic function Risk of hepatic or renal failure Adequate bone marrow (BM), renal, hepatic, and metabolic function (assessed ? 14 days before inclusion in the study): Subjects must have adequate bone marrow, renal and hepatic function and coagulation Adequate hepatic, renal and bone marrow function. Adequate hepatic and renal function defined as: Hepatic function: Adequate hematological, hepatic and renal functions. Hepatic lesion Adequate coagulation, renal and hepatic function Have adequate bone marrow and hepatic function. Adequate renal and hepatic function Participants must have adequate bone marrow, renal and hepatic function Adequate hepatic function Adequate renal, hepatic, pulmonary and cardiac function defined as: Adequate hematological, hepatic and renal function as defined in the protocol Subject has inadequate marrow, hepatic, and/or renal function at the Screening Visit defined as: Adequate hematological, renal, metabolic and hepatic function Adequate hepatic and renal function: Adequate hematological, renal, hepatic and coagulation laboratory test results. Adequate hepatic function within 28 days prior to registration for protocol therapy defined as meeting all of the following criteria: Patient has adequate hepatic function defined as: Patients must have adequate hepatic function, defined as Seriously limited cardiac, renal, or hepatic function Hepatic Subject must have adequate coagulation profile, renal, and hepatic function, per laboratory reference range at Screening Adequate hepatic, renal and pancreatic function. Hepatic encephalopathy Subjects must have adequate hepatic function as evidenced by: Adequate renal and hepatic function Adequate hepatic function is defined by the following: Adequate hematological, hepatic and renal function as defined in the protocol Hepatic encephalopathy Subjects must have adequate hepatic function as evidenced by: Hepatic and renal function meeting the strata below:\r\n* Group N: Hepatic: normal function (bilirubin =< ULN; AST =< ULN); renal: normal function (creatinine clearance [CrCl] >= 60 mL/min as estimated by the Cockcroft and Gault equation)\r\n* Group R3: Hepatic: normal function (bilirubin =< ULN; AST =< ULN); renal: severe dysfunction (CrCl >= 15 and < 30 mL/min as estimated by the Cockcroft and Gault equation)\r\n* Group R4: Hepatic: normal function (bilirubin =< ULN; AST =< ULN; renal: renal failure (hemodialysis)\r\n* Group H1: Hepatic: mild dysfunction (bilirubin =< ULN; AST > ULN); renal: acceptable function (CrCl >= 60 mL/min as estimated by the Cockcroft and Gault equation)\r\n* Group H2: Hepatic: moderate dysfunction (bilirubin > ULN and =< 3 x ULN; AST > ULN); renal: acceptable function (CrCl>=? 60 mL/min as estimated by the Cockcroft and Gault equation)\r\n* Group H3: Hepatic: severe dysfunction (bilirubin > 3 x ULN and up to investigators discretion; AST > ULN); renal: acceptable function (CrCl >= 60 mL/min as estimated by the Cockcroft and Gault equation) Adequate renal and hepatic function. Acceptable bone marrow, renal, and hepatic function based upon screening lab tests Subject must have adequate coagulation, renal, and hepatic function, per laboratory reference range at Screening. Adequate hematological, renal and hepatic function Adequate coagulation, renal and hepatic function Have adequate blood counts, hepatic and renal function Inadequate bone marrow, renal, or hepatic function as defined above, or an active coagulopathy that precludes tissue biopsy Subject must have adequate coagulation, renal, and hepatic function, per laboratory reference range at Screening. Adequate hepatic function as evidenced by serum bilirubin values < 2.0 mg/dL; ALT and/or AST < 3xULN. Adequate hepatic function Subject must have adequate bone marrow, renal and hepatic function. Subject must have adequate coagulation, renal, and hepatic function, per laboratory reference range at Screening. Adequate bone marrow, hepatic, renal and cardiac function Have clinically adequate hepatic and renal functions as defined by: Hepatic Adequate hepatic and renal function within protocol-defined parameters. Adequate hepatic function with bilirubin < 1.5 mg/dl Adequate hepatic, renal, and bone marrow function Adequate hepatic and renal function Patients with adequate bone marrow, renal and hepatic function: Adequate bone marrow independent of growth factor support, renal and hepatic function per defined laboratory criteria Adequate bone marrow reserve, hepatic and renal function Adequate bone marrow reserve, hepatic and renal function, as demonstrated by: Adequate baseline renal and hepatic function Adequate hepatic function. Adequate pulmonary, renal, hepatic, and cardiac function Immunotherapy: At least 42 days after the completion of any type of immunotherapy, e.g. tumor vaccines. Renal and Hepatic Function Adequate baseline renal and hepatic function Has adequate bone marrow reserve, hepatic and renal function, as demonstrated by: Adequate hematological, renal, hepatic, and coagulation laboratory assessments Adequate bone marrow, renal, and hepatic function. Adequate hepatic and renal function defined as: Patient having out of range laboratory values defined as: Hepatic and renal function: Must have adequate hepatic function Inadequate renal, hepatic or bone marrow function Adequate renal, hepatic, and bone marrow function demonstrated by protocol-specified laboratory parameters at the screening visit. Adequate bone marrow, hepatic and renal function as evidenced by: have adequate hepatic function and renal function Adequate hepatic function Adequate hepatic function Adequate bone marrow, renal capacity and hepatic function Adequate renal and hepatic function, as defined by the following criteria: Adequate hematological, hepatic, and renal function: Has adequate hepatic function as evidenced by: Adequate renal, hepatic, pulmonary and cardiac function defined as: Patients must have adequate hepatic function as documented by a serum bilirubin less than or equal to 2.5 mg/dL. Adequate hematological, renal, hepatic, and coagulation laboratory assessments Adequate baseline renal and hepatic function Adequate hematological, renal, hepatic and coagulation laboratory test results Adequate hematological, renal, and hepatic function Patients with history of hepatic dysfunction or hepatic disease and abnormal liver function tests; patients who have a history of hepatic dysfunction or hepatic disease and normal liver function tests will be eligible to participate Adequate hepatic, renal, and cardiac function Adequate hematological, renal, hepatic, and coagulation laboratory assessments Known active hepatic disease Adequate bone marrow, renal, hepatic, and metabolic function Renal and Hepatic Function Participants with abnormal hepatic function Adequate bone marrow, hepatic, and renal function tests within 30 days prior to enrollment: Subject has adequate bone marrow, renal and hepatic function at baseline, as demonstrated by the following: Adequate hepatic and renal function defined as: Adequate hepatic and renal function: No prior anticancer therapy for pancreatic cancer •? 18 years of age with a performance status of 0 or 1•Adequate complete blood counts, hepatic function, and renal function Have renal and hepatic function as defined by: Renal and Hepatic Function: Patient must have adequate renal and hepatic functions as indicated by the following laboratory values: Adequate hematology, hepatic and renal function laboratory values within 14 days prior to first dose of study drug. Adequate hepatic, renal, cardiac and hematological function Adequate renal and hepatic function Planned biopsy or resection of recurrent tumor for therapeutic and/or diagnostic purpose, and with adequate bone marrow, hepatic, cardiac, and renal function to undergo this planned procedure Adequate hematological, renal, metabolic and hepatic function Adequate baseline renal and hepatic function Adequate bone marrow, hepatic and renal function as evidenced by: Known hepatic cirrhosis Inadequate hematological, hepatic, or renal function Patients must have adequate hepatic function, defined as: Adequate renal and hepatic function and hematopoietic capacity Adequate hepatic and renal function Adequate bone marrow, hepatic, renal and cardiac function Adequate hematological, renal, hepatic, and coagulation laboratory assessments Hepatic: Hepatic function, as follows: The patient has adequate organ function, including cardiac, renal, and hepatic function: Evidence of laboratory abnormalities in standard renal, hepatic, or coagulation function tests Adequate hepatic and renal function Participants must have adequate hepatic and kidney function. Hepatic function, as follows: Recipient must have adequate hepatic function as defined by a total bilirubin <3x upper limit of normal or absence of hepatic fibrosis/cirrhosis. Adequate hepatic function: Adequate hepatic and renal function In hepatic dysfunction group, patients with hepatic dysfunction who have Gilbert's syndrome. Patients signs of encephalopathy (altered brain function). The participant has adequate bone marrow reserve, and renal and hepatic function Adequate hematologic function, hepatic function, renal function and coagulation function Adequate hepatic function per institutional standards adequate renal, hepatic and pancreatic function Adequate hepatic and renal function defined as: Patients with history of renal or hepatic insufficiency. Adequate Hepatic functions Adequate hepatic function. Adequate hepatic and renal function defined as: Adequate hematological, renal and hepatic function. Adequate hepatic function. Patients with history of hepatic dysfunction or hepatic disease and abnormal liver function tests (previously documented alanine aminotransferase greater than 40 IU/dL and/or plasma aspartate aminotransferase greater than 45 IU/d); patients who have a history of hepatic dysfunction or hepatic disease but whose most recent liver function tests have been documented as normal will be eligible to participate Chronic hepatic disease Patients with history of hepatic dysfunction or hepatic disease and abnormal liver function tests; patients who have a history of hepatic dysfunction or hepatic disease and normal liver function tests will be eligible to participate Adequate hepatic function defined as: Adequate renal and hepatic function Participant has adequate bone marrow, renal, hepatic and cardiac function. Adequate hematological, hepatic, renal and cardiac function Adequate bone marrow, renal, and hepatic function. Minocycline trial only: patients with adequate hepatic function according to MD Anderson testing standards Have adequate hematopoietic, hepatic, and renal function at a screening visit Patients must have adequate bone marrow, renal, hepatic, and sensory neurologic function to be eligible to receive platinum/taxane-based chemotherapy Adequate cardiac, renal, and hepatic functions. Adequate hepatic reserve Any significant cardiac, hepatic or renal disease Chronic renal diseases and hepatic cirrhosis Adequate hematological, renal, hepatic, and coagulation laboratory assessments Inadequate hepatic function No evidence of impaired hepatic or kidney function Adequate renal, hepatic, cardiac, and pulmonary function as evidenced by: Adequate hepatic function within 28 days prior to C1D1 Has adequate renal and hepatic function Adequate organ functions (hematological, hepatic, renal function) Patients with history of hepatic dysfunction or hepatic disease Adequate bone marrow, renal, hepatic, and blood clotting function Criteria 8, Adequate organ function within 4 wks prior to enrollment. This includes hematology, renal, hepatic and blood-clotting functions as defined by protocol. Adequate bone marrow, renal, hepatic, and metabolic function (assessed ? 7 days before inclusion in the study): Adequate bone marrow reserve and renal and hepatic function within 28 days before the first dose of study drug on the basis of the defined laboratory parameters. Adequate hematological, renal, and hepatic function