PTPN22 and rheumatoid arthritis: We also observed association with the PTPN22-1858C/T or PTPN22-1858T/T genotypes and we report for the first time an estimation of the association in the French Caucasian population for RF+ RA (34% versus 24%, P = 0.047, OR = 1.69, 95% CI = 1.03–2.78).