PTPN22 and rheumatoid arthritis: Stratification based on carriage or absence of shared epitope alleles (data not shown), on carriage of the PTPN22*620W gene susceptibility variant (odds ratio FCRL3-169*C allele = 1.12 (95% confidence interval 0.87–1.44), P = 0.37), on gender and on age at onset of RA similarly revealed no evidence for association of the SNPs in these subgroups (data not shown).