Normal volunteers and volunteers with lymphoid/hematopoietic malignancies may donate samples by apheresis, venipuncture, and bone marrow sampling on multiple occasions. Repeated donation by apheresis will be allowed as long as a period of at least eight week has elapsed since a previous apheresis. Repeated donations of peripheral blood or bone marrow will be allowed as long as a period of at least four weeks has elapsed since a previous donation. For any given volunteer, the total number of aphereses will not exceed six per year and the total number of peripheral blood or bone marrow donations will not exceed eight per year. All normal and CML volunteers must undergo repeat physical examination and complete blood count evaluation to determine eligibility prior to donation.