CTLA4 and type 1 diabetes mellitus: We have previously identified Cd247 as a candidate susceptibility gene in murine T1D [60, 61] and we found that the NOD allele of Cd247 confers impaired T cell activation, resulting in altered cytokine expression patterns, reduced proliferation and deficient CTLA-4 expression compared to the C57BL/6 (B6) allele of Cd247 [60].