Mycophenolate mofetil Recruiting Phase 2 Trials for Mantle Cell Lymphoma (MCL) / Recurrent Plasma Cell Myeloma / Secondary Myelodysplastic Syndromes / Myelodysplastic Syndrome / Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma / Chronic Myelogenous Leukemia, BCR-ABL1 Positive / Lymphoma, Hodgkins / Recurrent Acute Myeloid Leukemia With Myelodysplasia-Related Changes / Graft Versus Host Disease (GVHD) / Refractory Plasma Cell Myeloma / Follicular Lymphoma (FL) / Myeloproliferative Neoplasms / Leukemia, Acute / Lymphoma, Large B-Cell, Diffuse (DLBCL) / Marginal Zone Lymphoma Supportive Care