AIDS is a disease that progressively destroys that aspect of the body's defense called the immune system. It is particularly harmful to a class of cells called helper T-lymphocytes. The specific opportunistic infections and malignancies associated with AIDS have been treated with therapies that are often poorly tolerated by the patients and are associated with dose-limiting toxicities. The principal focus of AIDS therapy research at present is to control the underlying retroviral infection and to restore immune function with recombinant lymphokines, adoptive immunotherapy, and/or lymphocyte transplants. These treatments include zidovudine (AZT), which has been shown to control the HIV infection, and IFN-G, a lymphokine which activates tumor-destroying and germ-killing functions. Studies are needed to find the dose by which IFN-G works best.