The highest T1D genetic risk factor is a single polymorphism in the β chain of MHC class II molecule, H2-IAg7 in mice and human leukocyte antigen-DQ8 in humans within the amino acid for β57, which are responsible for antigen presentation by antigen-presenting cells (APCs) to CD4+ T cells (1). This evidence concerns the gene CD4 and type 1 diabetes mellitus.