CD4 and autoimmune disease: The IS-SCC group included tumors from 34 organ transplant patients (22 kidney, 1 liver, 2 lung, 1 heart, and 8 stem cell transplants), 4 patients with inflammatory or autoimmune disease receiving immunosuppressive medication (two for rheumatoid arthritis, one for psoriasis, one for bullous pemphigoid), 1 patient with a congenital immune deficiency (CD4+ T cell defect), and 1 patient with B-CLL requiring treatment (Table S3).