To be eligible for rhIL-7 administration, all Exclusion Criteria are prohibited. However, for the purpose of performing baseine pre-IL-7 procedures certain Exclusion Criteria designed to minimize specific complications from rhIL-7 (e.g., autoimmune or lymphoproliferative complications) but that do not increase the risk associated with these procedures are permitted, as baseline procedures will be done prior to IL-7 administration: #6, #11, through #13, #17, #18, #20, #22.