PTPN22 and type 2 diabetes mellitus: Such MDs include, for example, Alzheimer’s disease (AROE4), type-2 diabetes (PPARG, TCF7L2, KCNJ11), senile macular degeneration of the retina (CFH), systemic lupus erythematosus (JRF5), prostate cancer (region JF1H), type-1 diabetes (IL2RA, CD25, PTPN22), autoimmune thyroiditis (CTLA4), hirschsprung disease (RET), Crohn’s disease (NOD2, CARD15), and rheumatoid arthritis (PTPN22) [8, 34].