PTPN22 and autoimmune polyendocrinopathy: Nonetheless, the results of our study, conducted in an ethnically homogenous, clinically well-characterized APS cohort, indicate that rs3757247 is apparently one of the universal genetic markers of autoimmunity, such as HLA, PTPN22, CTLA4. However, establishing a reliable set of polymorphisms to predict multiplex autoimmunity, is a matter of further cross-sectional association analyses in several populations, followed by prospective validation studies in at-risk cohorts.