Mycophenolate mofetil Active Not Recruiting Phase 2 Trials for Juvenile Myelomonocytic Leukemia (JMML) / Leukemia Acute Myeloid Leukemia (AML) / Hemoglobinuria, Paroxysmal Nocturnal (PNH) / Myelodysplastic Syndromes (MDS) / Leukemia, Myeloid, Chronic(CML) / Lymphoma, Non-Hodgkin (NHL) / Leukemia, Acute Lymphocytic (ALL) / Lymphoma, Hodgkins Treatment