Interferon (IFN)-gamma is an important immune regulator in normal immunity. When IFNgammaproduction is disturbed, various autoimmune diseases (ADs) can develop, in which we suggest that anti-IFNgamma could have a beneficial effect. Depending on the cell type in which IFNgamma synthesis is disturbed, different clinical manifestations may result. We have also proposed to remove tumor necrosis factor (TNF)alpha, together with certain types of IFNs, to treat various ADs and AIDS, also an autoimmune condition. Anti-IFNgamma has been tested in several T-helper cell (Th1) ADs, including rheumatoid arthritis (RA), multiple sclerosis (MS), corneal transplant rejection, uveitis, Type 1 diabetes, schizophrenia (anti-IFNgamma and anti-TNFalpha), and various autoimmune skin diseases (alopecia areata, psoriasis vulgaris, vitiligo, pemphigus vulgaris and epidermolysis bullosa). A strong, sometimes striking, therapeutic response followed administration of anti-IFNgamma, indicating that it may be a promising therapy for Th1 ADs.