Evidence of a significant uncontrolled concomitant disease of the nervous system, pulmonary, autoimmune, renal, hepatic, endocrine, or gastrointestinal disorders; or a serious non-healing wound or fracture Evidence or history of other significant, hepatic, renal, ophthalmologic, psychiatric, or gastrointestinal disease which would likely increase the risks of participating in the study. Clinically significant acute or unstable cardiovascular, cerebrovascular (stroke), renal, gastrointestinal, pulmonary, immunological, endocrine, or central nervous system disorders. Clinically significant cardiac, respiratory, gastrointestinal, renal, hepatic or neurological conditions. Patients with a known history of drug abuse or any chronic neurologic, psychiatric, endocrine, metabolic, immunologic, hepatic or renal disease (including a history of hemolytic uremic syndrome) that in the opinion of the Investigator would adversely affect study participation. 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. Significant history of renal, neurologic, psychiatric, endocrinologic, metabolic, immunologic, cardiovascular or hepatic disease, within the last 6 months that, in the opinion of the investigator, would adversely affect his/her participation in the study. Patient has significant and/or uncontrolled cardiac, renal, hepatic or other systemic disorders or significant psychological conditions at baseline visit that in the investigator’s judgment would jeopardize subject enrollment or compliance with the study procedures Subject has any history of clinically significant condition(s) that in the opinion of the investigator would adversely affect his/her participating in this study including, but not limited to:\r\n* New York Heart Association heart failure > class 2\r\n* Renal, neurologic, psychiatric, endocrinologic, metabolic, immunologic, hepatic, cardiovascular disease, or bleeding disorder independent of leukemia Participant has chronic respiratory disease that requires continuous oxygen, or significant history of renal, neurologic, psychiatric, endocrinologic, metabolic, immunologic, hepatic, cardiovascular disease, any other medical condition or known hypersensitivity to any of the study medications including excipients of azacitidine that in the opinion of the investigator would adversely affect his/her participating in this study. Acute or chronic, clinically significant hematologic, pulmonary, cardiovascular, or hepatic or renal functional abnormality as determined by the investigator based on medical history, physical examination, electrocardiography (EKG), and/or laboratory screening test Acute or chronic, clinically significant hematologic, pulmonary, cardiovascular, hepatic renal, and/or other functional abnormality that would jeopardize the health and safety of the participant as determined by the investigator based on medical history, physical examination, laboratory values, and/or diagnostic studies Participant has chronic respiratory disease that requires continuous oxygen, or significant history of renal, neurologic, psychiatric, endocrinologic, metabolic, immunologic, hepatic, cardiovascular disease, any other medical condition or known hypersensitivity to any of the study medications including excipients of LDAC that in the opinion of the investigator would adversely affect his/her participating in this study. Major medical conditions that might affect study participation (e.g. uncontrolled pulmonary, renal, or hepatic dysfunction, uncontrolled serious infection, cardiac disease) The subject has a history of advanced cardiac, hepatic or renal disease or other chronic illness History of renal or hepatic disease, including history of hepatitis B or C Current signs or symptoms of severe progressive or uncontrolled hepatic, hematologic, gastrointestinal, endocrine, pulmonary or cardiac disease other than directly related to RCC Acute or chronic, clinically significant hematologic, pulmonary, cardiovascular, or hepatic or renal functional abnormality as determined by the investigator based on medical history, physical examination, electrocardiogram (EKG), and/or laboratory screening test Patients with renal, hepatic, pulmonary, or cardiac disease that exclude delivery of standard chemotherapy Significant active renal, neurologic, psychiatric, hepatic or endocrinologic disease that in the investigator's opinion would adversely impact on his/her participating in the study. Significant cardiac, pulmonary, metabolic, renal, hepatic, gastrointestinal or autoimmune conditions that in the opinion of the investigator places the subject at an unacceptable risk as participant in this trial Acute or chronic, clinically significant hematologic, pulmonary, cardiovascular, or hepatic or renal functional abnormality as determined by the investigator based on medical history, physical examination, electrocardiogram (EKG), and/or laboratory screening test Subjects must not have a history of any significant renal or hepatic disease requiring ongoing medical therapy or clinical intervention No overt renal, hepatic, cardiac or pulmonary disease A serious, unstable illness, as judged by the Investigator, during the past 3 months before screening/baseline visit including but not limited to: hepatic, renal, gastro-enterologic, respiratory, cardiovascular, endocrinologic, neurologic or immunologic disease; Has significant renal or hepatic disease, uncontrolled or severe cardiovascular or pulmonary diseases, or other uncontrolled medical condition that, based on the Investigator's assessment, would compromise the patient's ability to tolerate study treatment or the assessment of treatment response. Patients with significant concurrent, uncontrolled medical condition including, but not limited to, cardiovascular, renal, hepatic, gastrointestinal, endocrine, pulmonary, neurological, cerebral or psychiatric disease which in the opinion of the investigator may represent a risk for the patient, are NOT eligible Evidence of current serious uncontrolled concomitant cardiovascular nervous system, pulmonary (including obstructive pulmonary disease), renal, hepatic, endocrine (include uncontrolled diabetes mellitus) or gastrointestinal disease Any evidence of severe or uncontrolled systemic disease such as clinically significant cardiovascular, pulmonary, hepatic, renal or metabolic disease No overt renal, hepatic, cardiac or pulmonary disease Evidence of clinically significant disease (e.g., cardiovascular, respiratory, gastrointestinal, renal disease) that in the opinion of the investigator(s) could affect the participant's safety or interfere with the study assessments. History of or ongoing major cardiac, pulmonary, renal, endocrine, or hepatic disease that, in the opinion of the investigator or sponsor, would preclude participation. History of or ongoing major cardiac, pulmonary, renal, endocrine, or hepatic disease that, in the opinion of the investigator or sponsor, would preclude participation. Significant history of renal, neurologic, psychiatric, endocrinologic, metabolic, immunologic, cardiovascular, or hepatic disease No active autoimmune disease or uncontrolled infection, normal bone marrow, renal, hepatic function, FEV1 > 1.2L, no significant underlying heart or lung disease Participant has a significant history of renal, neurologic, psychiatric, endocrinologic, metabolic, immunologic, hepatic, cardiovascular disease, or any other medical condition that in the opinion of the investigator would adversely affect his/her participating in this study. Significant concurrent, uncontrolled medical condition including, but not limited to, renal, hepatic, gastrointestinal, endocrine, pulmonary, neurological, cerebral or psychiatric disease which in the opinion of the investigator may represent a risk for the participant A history of significant renal, neurologic, psychiatric, endocrine, metabolic, immunologic, cardiovascular or hepatic disease Evidence of clinically significant disease (e.g., cardiovascular, respiratory, gastrointestinal, renal disease) that in the opinion of the investigator could affect the subject safety or interfere with the study assessments Evidence or history of other significant cardiac, hepatic, renal, ophthalmologic, psychiatric, or gastrointestinal disease which would likely increase the risks of participating in the study. The specific type of stress test will be selected at the PI's discretion. Significant history of renal, neurologic, psychiatric, endocrinologic, metabolic, immunologic, cardiovascular, pulmonary or hepatic disease, that in the opinion of the investigator, would adversely affect his/her participation in the study. Significant concurrent, uncontrolled medical condition including, but not limited to, renal, hepatic, gastrointestinal, endocrine, pulmonary, neurological, cerebral or psychiatric disease which in the opinion of the investigator may represent a risk for the patient History of significant renal, neurologic, psychiatric, endocrinologic, metabolic, immunologic, cardiovascular, or hepatic disease Systemic diseases (cardiovascular, renal, hepatic, etc) that would prevent study treatment in the investigator's opinion. Significant concurrent, uncontrolled medical condition including, but not limited to, renal, hepatic, gastrointestinal, endocrine, pulmonary, neurological, cerebral or psychiatric disease which in the opinion of the investigator may represent a risk for the patient\r\n* Those patients with medical conditions that are controlled with medical therapy are eligible Subject has a significant history of renal, neurologic, psychiatric, endocrinologic, metabolic, immunologic, or hepatic disease that in the opinion of the Investigator would adversely affect his/her participating in this study. Significant concurrent, uncontrolled medical condition including, but not limited to, renal, hepatic, gastrointestinal, endocrine, pulmonary, neurological, cerebral or psychiatric disease which in the opinion of the investigator may represent a risk for the patient Significant concurrent, uncontrolled medical condition including, but not limited to, renal, hepatic, gastrointestinal, endocrine, pulmonary, neurological, cerebral or psychiatric disease which in the option of the investigator may represent a risk for the patient Subject has a significant history of renal, neurologic, psychiatric, pulmonary, endocrinologic, metabolic, immunologic, cardiovascular, or hepatic disease that in the opinion of the Investigator would adversely affect his/her participating in this study. Nonmalignant systemic disease (cardiovascular, renal, hepatic, etc.) that would preclude any of the study therapy drugs. History or clinical evidence of any surgical or medical condition which the investigator judges as likely to interfere with the results of the study or pose an additional risk in participating (eg, active or clinically significant history of disease involving a major organ system—vascular, cardiac, pulmonary, hepatic, gastrointestinal, gynecologic, hematologic, neurologic, neoplastic, renal, endocrine or immunodeficiency, autoimmune or clinically significant active psychiatric disorders) Nonmalignant systemic disease (cardiovascular, renal, hepatic, etc.) that would preclude the patient from being subjected to surgical excision Systemic disease that would prevent study treatment (uncontrolled hypertension, cardiovascular renal, hepatic (including Child-Pugh Class B and C) or metabolic disease) The donor currently has or had a history of any clinically relevant gastrointestinal, hematologic, respiratory, psychiatric, renal, hepatic, cardiac, metabolic (eg, fructose intolerance), neurological, or any other disease or condition which may influence the physiological metabolic turnover (eg, severe endocrine diseases, febrile condition, severe infections Significant disease or uncontrolled disease, i.e. cardiovascular renal, hepatic, endocrine, metabolic, neurologic; or other significant disease that would limit the patients ability to participate in the study as determined by the investigator or medical monitor. Significant, concurrent, uncontrolled medical condition including but not limited to, renal, hepatic, hematological, gastrointestinal, endocrine, pulmonary, cardiac, neurological, cerebral, or psychiatric disease. Uncontrolled concomitant medical conditions, including, but not limited to, renal, hepatic, hematologic, gastrointestinal, endocrine, pulmonary, neurological, cerebral, or psychiatric diseases. Significant concurrent, uncontrolled medical condition including, but not limited to, renal, gastrointestinal, endocrine, pulmonary, neurological, cerebral or psychiatric disease which in the opinion of the investigator may represent a risk for the patient Evidence of significant uncontrolled concomitant diseases, such as ocular toxicities, diabetes, cardiovascular disease; nervous system, renal, hepatic, endocrine, or gastrointestinal disorders; autoimmune disease, or a serious non-healing wound or fracture Clinical or laboratory signs and symptoms of significant cerebral, cardiovascular, respiratory, renal, hepatobiliary, pancreatic or infectious disease, which in the Investigator's judgment may interfere with the study assessment or completion of the study. Clinically significant pulmonary, endocrine, neurologic, hematologic, gastrointestinal (GI), autoimmune, psychiatric or genitourinary disease unrelated to HCC that in the judgment of the investigator should preclude treatment with dalantercept or sorafenib. Subject has a significant history of cardiovascular disease (e.g., myocardial infarction [MI], thrombotic or thromboembolic event in the last 6 months), renal, neurologic, psychiatric, endocrinologic, metabolic, immunologic, or hepatic disease that in the opinion of the Investigator would adversely affect his/her participating in this study Clinically significant acute or unstable cardiovascular, cerebrovascular (stroke), renal, gastrointestinal, pulmonary, immunological, endocrine, or central nervous system disorders Evidence of significant uncontrolled concomitant diseases, such as cardiovascular disease, nervous system, pulmonary, renal, hepatic, endocrine, or gastrointestinal disorders; or a serious non-healing wound or fracture Other significant concurrent, uncontrolled medical conditions including, but not limited to, renal, hepatic, autoimmune, hematological, gastrointestinal, endocrine, pulmonary, neurological, cerebral or psychiatric disease which, in the Investigator's opinion, will impact study participation. Other significant concurrent, uncontrolled medical conditions including, but not limited to, renal, hepatic, autoimmune, hematological, gastrointestinal, endocrine, pulmonary, neurological, cerebral or psychiatric disease which, in the investigator's opinion, will impact study participation. No unstable neurologic, hepatic, renal, cardiovascular, lymphatic, or metabolic disease Has a clinically significant cardiovascular, dermatologic, endocrine, gastrointestinal, hematologic, infectious, metabolic, neurologic, psychologic, or pulmonary disorder or any other condition, including excessive alcohol or drug abuse, or secondary malignancy, that may interfere with study participation in the opinion of the investigator. Evidence of clinically significant disease (e.g., cardiovascular, respiratory, gastrointestinal, renal, or infectious disease) that in the opinion of the investigator(s) could affect the participant's safety or interfere with the study assessments Medical conditions felt to be clinically contributing to fatigue based on the investigator’s history, physical examination, and assessment: anemia (hemoglobin less than 10 g/dl), hypothyroidism (thyroid stimulating hormone greater than 4.6 MCU/mL), uncontrolled pain, medical problems associated with fatigue: chronic obstructive pulmonary disease, congestive heart failure, renal disease, hepatic dysfunction, autoimmune disease, neurological disorders such as multiple sclerosis or Parkinson’s disease, and poorly controlled sleep apnea History or presence of any significant cardiovascular, pulmonary, hepatic, renal, gastrointestinal, gynecological, endocrine, immunological, dermatological, neurological or psychiatric disease or disorder that, in the opinion of the investigator, contraindicates participation. Medical conditions felt to be clinically contributing to fatigue based on the investigator’s history, physical examination, and assessment: anemia (hemoglobin less than 10 g/dl), hypothyroidism (thyroid stimulating hormone greater than 4.6 MCU/mL), uncontrolled pain, medical problems associated with fatigue: chronic obstructive pulmonary disease, congestive heart failure, renal disease, hepatic dysfunction, autoimmune disease, neurological disorders such as multiple sclerosis or Parkinson’s disease, and poorly controlled sleep apnea Pulmonary disease, renal dysfunction, hepatic disease, cardiac disease, neurologic disease; Any significant cardiac, hepatic or renal disease Evidence of hematopoietic, cardiovascular, hepatic, renal, neurologic, psychiatric, dermatologic, immune disorder, or other disease that may interfere with assessment of safety or efficacy of vaccine activity as indicated in study objectives Acute or chronic, clinically significant pulmonary, cardiovascular, hepatic or renal dysfunction, which in the opinion of the investigator precludes administration of the study vaccine Acute or chronic, clinically significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by physical examination or laboratory screening tests. Clinically relevant hepatic, neurological, pulmonary, ophthalmological, endocrine, renal, or other major systemic disease making implementation of the protocol or interpretation of the study results difficult, or that would put the subject at risk by participating in the study in the opinion of the Investigator. History or current evidence of significant cardiovascular, pulmonary, hepatic, renal, gastrointestinal, hematological, endocrinological, metabolic, neurological, psychiatric, or other diseases, which, in the opinion of the investigator, may affect the subject's safety or interfere with the trial. Severe or uncontrolled/unstable cardiac, pulmonary, hepatic or renal disease, including MI or CVA within 3 months prior to treatment.