HLA antigens have been associated with a variety of diseases. Our studies concentrate on malignant diseases, disorders of immunity and psychoses. We are testing the hypothesis generated by our previous work that long-term survival in leukemia and lung cancer is due to the possession of certain HLA antigens. Other diseases studied include melanoma, acute schizophrenia and manic-depressed psychoses. It is too early to report on HLA and survival in leukemia and lung cancer, although at diagnosis there appears to be an abnormal distribution of HLA-A antigens in leukemia. HLA-A2 is elevated significantly (p less than 0.02) in acute schizophrenia; there appears to be no HLA association with manic-depressed psychoses.