Additionally, other genes such as NOD2 (Crohn’s disease), IBD5 (IBD), PTPN22 (T1D, RA, SLE and Graves’ disease), CTLA4 (T1D), IL23R and TYK2, have been implicated as AID risk factors [8,12,13,14,15,16]. Here, PTPN22 is linked to rheumatoid arthritis.