Factors Affecting Post-transplant Cyclophosphamide (PTCy) Efficacy

This study examines why a certain chemotherapy drug given after a stem cell transplant (called post-transplant cyclophosphamide) works better in some patients than others, by collecting blood and tissue samples from transplant patients and their donors. **You may be eligible if...** - You are 18 years or older - You are scheduled to receive a stem cell (bone marrow) transplant at Levine Cancer Institute using a reduced-intensity (non-myeloablative) approach - You are eligible for a transplant from a half-matched family member (haploidentical), a fully matched family member, or an unrelated matched donor - You are planned to receive post-transplant cyclophosphamide as part of your care **You may NOT be eligible if...** - You do not meet the transplant eligibility criteria set by your doctor - You are not scheduled for one of the specific transplant types listed in the protocol Talk to your doctor to see if this trial is right for you.