i. For patients with leukemia: bone marrow aspirate defined as <5% blasts, absence of cytogenetic abnormality by FISH or karyotype (if applicable) and no evidence of CSF involvement (if applicable) ii. For patients with solid tumors remission will be determined by appropriate radiologic scans, and other tests, including bone marrow aspirate and biopsies demonstrating absence of extrinsic cells and absence of specific FISH or cytogenetic abnormality (if applicable), iii. For patients with lymphoma, remission will be determined by bone marrow aspirate and biopsy, radiologic scans and other tests. Bone marrow will show <5% blasts, absence of cytogenetic abnormality by FISH or karyotype (if applicable), and flow cytometry (if lymphoma specific marker present) and absence of CNS disease by spinal fluid (if applicable)