I. Evaluating the genetic impact on the occurrence of RA the T allele of rs2476601 (PTPN22) (bivariate: p < 0.001; multivariate: p = 0.018) and T allele of rs2240340 (PADI4) (bivariate: p = 0.006; multivariate: p = 0.070) were associated with an increased vulnerability to RA. The gene discussed is PADI4; the disease is rheumatoid arthritis.