The association of specific human leukocyte antigen (HLA) class II alleles (DR4, DQ8, DQ2) with a heightened genetic risk for T1D implies a crucial role for HLA II-restricted CD4 T cells in the development of the disease, influencing B cell responses, antibody production, CD8 T cell activity, and stimulation of islet-resident macrophages [19, 32, 33]. This evidence concerns the gene CD4 and type 1 diabetes mellitus.