Research samples will be collected from participants when blood is drawn or bone marrow, urine, or stool is collected, or tumor or other tissue is biopsied as part of their general medical care. Investigators may periodically request an additional sample of blood, stool, or urine. Participants who are 18 years of age or older may donate a large number of white blood cells through a procedure called leukapheresis. This procedure is not part of general medical care and would be done for research purposes only. For apheresis, a catheter (plastic tube) is placed in a vein in the subject's arm. Blood flows from the vein into a cell separator machine, where the white cells are separated from the red cells, platelets, and plasma by a spinning process. The white cells are removed and collected, and the rest of the blood is returned to the subject through a second tube placed in the other arm.