This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of this study is to understand why certain individuals are at increased risk of developing Myelodysplastic Syndrome (MDS) or Acute Myelogenous Leukemia (AML). Rarely, patients develop AML or MDS after having undergone BMT or PSCT for lymphoma. MDS is a disease of the bone marrow and blood. AML is a malignant disease (cancer) of the bone marrow and blood. Patients with AML have uncontrolled growth of a certain type of blood cell called myeloid cells. On the other hand, in patients with MDS, the bone marrow produces too few red blood cells, white blood cells and platelets. Since only a small fraction of patients develop therapy-related MDS or AML, it may be that some patients are more likely to develop genetic changes from exposure to chemotherapy either before or at the time of transplant. Our goal is to be able to identify individuals at increased risk of these complications. In this study, 1) bone marrow and/or blood samples will be examined for genetic mutations (changes) and for factors that might lead to increased risk of mutation, 2) questionnaires will be filled out, and 3) information on exposure research subjects have received will be gathered from the medical charts.