INCLUSION CRITERIA:
Subjects will be entered on this protocol at the time of their first visit to the NIH Clinical Center outpatient clinic or inpatient service if:
The subject carries the diagnosis of a disorder for which the Hematology Branch has an active research protocol, and based on information received from an outside physician, he/she appears to meet at least preliminary eligibility criteria for that protocol.
OR
The subject is a donor for a subject for which the Hematology Branch has an active stem cell transplant protocol and based on information received from an outside physician, he/she appears to meet preliminary eligibility as a donor.
OR
The subject is a normal volunteer for which the Hematology Branch has an active study recruiting healthy normal volunteers and he/she appears to meet preliminary eligibility as a normal volunteer.
Age greater than or equal to 2.
Weight greater than 12 kg.
The subject or the subject's guardian is capable of informed consent, and willing to sign the consent form after initial counseling by clinical staff. Separate consent forms for all interventional or surgical procedures will be obtained after explanation of the specific procedure.