CTLA4 and type 1 diabetes mellitus: In addition to the HLA genes, 60 plus non-HLA risk alleles were shown to be involved in T1D pathogenesis, including several genetic variants in key immune genes such as the insulin gene (INS), the protein tyrosine phosphatase non-receptor type 22 gene (PTPN-22), the cytotoxic T-lymphocyte-associated protein 4 gene (CTLA4), the interleukin 2 receptor alpha (IL-2RA), and interferon-induced with helicase C domain 1 (IFIH1) in addition to PXK/PDHB and PPIL2 genes [22,26,27,33,34,35,36].