HLA-C and type 1 diabetes mellitus: There is no cure for T1D, which develops in children and young adults, and is associated with multiple complications and early mortality.1 The non-obese diabetic (NOD) mouse model of autoimmune diabetes shares many features with human T1D, including a number of regions of genetic overlap, multiple common autoantigens, shared MHC structure, as well as a marked influence of the environment on incidence.2 Nevertheless, translation of conclusions drawn from an inbred mouse strain in a controlled environment, to outbred humans has proven problematic.