In particular, the following genes have been identified as being associated with T1DM: PTPN22 (protein tyrosine phosphatase non-receptor type 22), INS (insulin), CTLA4 (cytotoxic T-lymphocyte-associated protein 4), and IL2RA (interleukin 2 receptor alpha) [13]. Here, PTPN22 is linked to type 1 diabetes mellitus.