Patients enrolled in NIH protocol 95-I-0133 at the Clinical Center may participate in an extension phase of this study in which the drug prednisone will be eliminated from the treatment regimen. Prednisone is associated with avascular necrosis, a condition that has been found in a number of patients in this study. Also, certain patients in this protocol may receive future interleukin-2 treatment cycles at home. Home administration of IL-2 injections involves less frequent data and safety monitoring and no medical evaluations at the Clinical Center except at the beginning of each cycle.