The purpose of this study is to develop tests that will allow doctors to identify genetic differences that may indicate how a patient may respond to cancer chemotherapy and/or the drugs used to prepare for bone marrow transplantation. Patients in this study will include pediatric patients with cancer and patients who will be undergoing a bone marrow transplant.
Investigators will take swabs from the inside of each patient’s cheek as well as blood samples for these genetic tests. These tests will be performed in addition to the usual tests in these patients. Researchers will see if the results of these tests are related to the side effects and effectiveness of the drugs the patients receive. The test results will not alter the course of a patient’s treatment.