Previous studies have shown that the SNPs of PTPN22 and CTLA-4 are associated with T1DM [38–43] and other autoimmune diseases [44–47], which have some meta-analysis to support it [48–51].Our research showed statistical evidence that the polymorphism of genes PTPN22 rs2476601 and CTLA-4 rs231775 is associated with LADA on the basis of population study, which could provide some clues on the research of fundamental to diabetes biology and uncover the major genetic factors involved in the pathogenesis of LADA. Here, PTPN22 is linked to diabetes mellitus.