HLA-C and type 1 diabetes mellitus: In 1994, during a short sabbatical in the laboratory of Dr. Luciano Adorini in Milan, we (LCH and MCH) purified HLA class II proteins that confer high risk for T1D and the equivalent single major histocompatibility complex (MHC) protein, I-Ag7, of the nonobese diabetic (NOD) mouse, a model of T1D.