Patients must NOT be receiving valproic acid, an histone deacetylase (HDAC) inhibitor, and may not have previously received any HDAC inhibitor prior to enrollment (e.g. valproic acid, entinostat, vorinostat) unless discussed with the study chair; patients must not have received prior HDAC therapy for the treatment of their malignancy Concurrent use or anticipated need for medications that are mainly metabolized by UGT1A9 including their administration within 7-days prior to the first dose of study drug (e.g., raloxifene, valproic acid, propofol, propranolol, dapagliflozin, darexaban, mycophenolic acid, and tapentadol) Concomitant therapy with valproic acid/valproate-containing therapies Patients who are being treated with Valproic Acid for any of its indication (epilepsy, mood disorder) must be excluded or must stop using the medication. Patients requiring concurrent administration of valproic acid are not eligible for this trial Prior treatment with histone deacetylase (HDAC) inhibitors (e.g. valproic acid, Zolinza (SAHA), romidepsin (Istodax) Has taken valproic acid, or another histone deacetylase inhibitor, within 2 weeks prior to study day 1 Prior histone deacetylase (HDAC), deacetylase (DAC), heat shock protein (HSP)90 inhibitors or valproic acid for the treatment of cancer is allowed Patients who will need valproic acid for any medical condition during the study or within 5 days prior to first panobinostat treatment Patients who have received histone deacetylase (HDAC) inhibitors (including valproic acid, entinostat, vorinostat) are excluded Patients with a prior history of treatment with histone deacetylase (HDAC) inhibitors (e.g., SNDX-275/entinostat, LAQ-824, LBH589, PXD-101/belinostat, etc); patients who have received valproic acid will be excluded from this study Needing valproic acid for any medical condition during the study or within 5 days prior to first panobinostat treatment Patients should not have taken valproic acid or another histone deacetylase inhibitor for at least 2 weeks prior to enrollment History of severe allergic reaction to sunitinib or valproic acid; inability to receive sunitinib or valproic acid Previous treatment with sunitinib or valproic acid for uveal melanoma Active treatment with valproic acid for non-oncological conditions, if this cannot be safely switched to an alternative agent Prior myelosuppressive chemotherapy or other investigational drug therapy within the last 6 months prior to initiation of sunitinib or valproic acid Patients taking concomitant histone deacetylase (HDAC) inhibitors; use of HDAC inhibitor like compounds such as valproic acid for epilepsy is permitted if there is at least a 2 week wash out Any condition that would prohibit patient from initiating valproic acid; current or prior valproic acid treatment is allowed (do not need to be >= lower limit of normal [LLN] for laboratory for enrollment) History of valproic acid (VPA) use Patients must not have received valproic acid within 30 days of study entry Patients requiring concomitant therapy with phenytoin, phenobarbital, carbamazepine, or valproic acid Prior anti-cancer treatment with MLN9708 (ixazomib), histone deacetylase (HDAC), deacetylase (DAC), heat shock protein (HSP)90 inhibitors or valproic acid Patients who will need valproic acid for any medical condition during the study or within 5 days prior to first panobinostat treatment Use of any UDP glucuronosyltransferase 1 family, polypeptide A9 (UGT1A9) inhibitor including: acitretin, amitriptyline, androsterone, cyclosporine, dasatinib, diclofenac, diflunisal, efavirenz, erlotinib, estradiol (17-beta), flutamide, geftinib, gemfibrozil, glycyrrhetinic acid, glycyrrhizin, imatinib, imipramine, ketoconazole, lineoleic acid, mefenamic acid, mycophenolic acid, niflumic acid, nilotinib, phenobarbital, phenylbutazone, phenytoin, probenecid propofol, quinidine, ritonavir, Sorafenib, sulfinpyrazone, valproic acid and verapamil from screening through follow-up period Patients asking or who have had prior treatment with a drug like vorinostat (i.e., valproic acid) within the last 30 days Participants should not have taken valproic acid or another histone deacetylase inhibitor for at least 2 weeks prior to study enrollment Patient had prior treatment with an histone deacetylase (HDAC) inhibitor (e.g., romidepsin [Depsipeptide], NSC-630176, MS 275, LAQ-824, belinostat [PXD-101], LBH589, MGCD0103, CRA024781, etc); patients who have received compounds with HDAC inhibitor-like activity, such as valproic acid, as anti-tumor therapy should not enroll in this study; patients who have received such compounds for other indications, e.g. valproic acid for epilepsy, may enroll after a 30-day washout period Patients should not have taken valproic acid or another histone deacetylase inhibitor for at least 2 weeks prior to enrollment Patient needing valproic acid during the study or within 5 days prior to first dose Patients who will need valproic acid for any medical condition during the study or within 5 days prior to first PANOBINOSTAT treatment Patients receiving histone deacetylase (HDAC) inhibitors or compounds with HDAC inhibitor like activity, such as valproic acid, are ineligible; patients who have received such agents may enroll on this study after a 14-day washout period Patients who will need valproic acid for any medical condition during the study or within 5 days prior to first panobinostat treatment Patients who will need valproic acid for any medical condition during the study or within 5 days prior to first panobinostat treatment Valproic acid for the treatment of cancer Patients who will need valproic acid for any medical condition during the study or within 5 days prior to first panobinostat treatment Prior histone deacetylase (HDAC), deacetylase (DAC), heat shock protein 90 (HSP90) inhibitors or valproic acid for the treatment of cancer Patients who will need valproic acid for any medical condition during the study or within 5 days prior to first panobinostat treatment Allergy to valproic acid Patients who have had prior treatment with a histone deacetylase (HDAC) inhibitor (e.g., romidepsin [Depsipeptide], NSC-630176, MS 275, LAQ-824, belinostat [PXD-101], LBH589, MGCD0103, CRA024781, etc); patients who have received compounds with HDAC inhibitor-like activity, such as valproic acid, as anti-tumor therapy should not enroll in this study; patients who have received such compounds for other indications, e.g. valproic acid for epilepsy, may enroll after a 30-day washout period Patient had prior treatment with an histone deacetylases (HDAC) inhibitor (e.g., romidepsin [Depsipeptide], NSC-630176, MS 275, LAQ-824, belinostat [PXD-101], LBH589, MGCD0103, CRA024781, etc); patients who have received compounds with HDAC inhibitor-like activity, such as valproic acid, as anti-tumor therapy should not enroll in this study; patients who have received such compounds for other indications, e.g. valproic acid for epilepsy, may enroll after a 30-day washout period Concurrent use of valproic acid is not allowed Patients receiving valproic acid (VPA), an anticonvulsant drug with HDAC inhibitor properties, will be excluded, unless they are switched to an alternative agent prior to treatment initiation. No wash out period is required. Prior HDAC, deacetylase (DAC), heat shock protein (HSP)90 inhibitors or valproic acid for treatment of cancer Patients who will need valproic acid for any medical condition during the study or within 5 days prior to first panobinostat treatment Patients will be excluded if they are receiving Valproic Acid (VPA) therapy. Patients may not have taken another histone deacetylase inhibitor (i.e. valproic acid, vorinostat) for at least 2 weeks prior to enrollment Concurrent use of other histone deacetylase inhibitors (e.g. valproic acid) are prohibited except for histone deacetylase (HDAC) inhibitors or HDAC-inhibitor like agents used for non-cancer treatment (e.g. epilepsy), where a 14 day washout is allowed RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patients have had valproic acid within 28 days prior to enrollment Prior histone deacetylases (HDAC), deacetylase (DAC), heat shock protein 90 (HSP90) inhibitors or valproic acid for the treatment of cancer Patients who will need valproic acid for any medical condition during the study or within 5 days prior to first LBH589 treatment Patients should not have taken valproic acid, another histone deacetylase (HDAC) inhibitor, for at least 2 weeks prior to enrollment Patients will be excluded if they have received previous therapy with HDAC, DAC, HSP90 inhibitors or valproic acid anticancer therapy. Valproic acid therapy is not allowed for any reason while on this study. Patients must not be receiving valproic acid Patients who will need valproic acid for any medical condition during the study or within 5 days prior to first panobinostat treatment Treatment with valproic acid within 14 days prior to initiation of study and during the study Prior use of valproic acid or any other histone deacetylase (HDAC) inhibitor for lymphoma treatment Use of valproic acid for any medical condition while receiving protocol treatment or within 5 days prior to first panobinostat dose For subjects assigned to take vorinostat, prior exposure to vorinostat or other known histone deacetylase (HDAC) inhibitors for cancer therapy; patients should not have taken valproic acid, another histone deacetylase inhibitor, for at least 2 weeks prior to study enrollment; note: this criterion does NOT apply to subjects treated on the Expansion Cohort (accruals post February 1, 2013) Prior therapy with other histone deacetylase (HDAC) inhibitors, including valproic acid Patients requiring concurrent administration of valproic acid are also excluded Patients currently taking valproic acid Histone deacetylase (HDAC), deacetylase (DAC), heat shock protein (HSP)90 inhibitors or valproic acid for the treatment of cancer within 30 days; only Food and Drug Administration (FDA) approved drug are vorinostat and romidepsin the rest are considered investigational and are not allowed Patients who will need valproic acid for any medical condition during the study or within 5 days prior to first PANO treatment Any contraindication to dexamethasone or valproic acid such as known allergies or sensitivity