Historical studies have revealed that immune tolerance within the T cell compartment, which is essential to limit autoimmune disease, operates through host MHC restriction and TCR clonotype diversity and specificity (Burnet, 1976; Lederberg, 1959; Sell and Gell, 1965; Talmage, 1957; Zinkernagel and Doherty, 1974). The gene discussed is HLA-C; the disease is autoimmune disease.