In the initial multivariate analysis, which used the absolute change in the DAS28 over 6 months as the primary outcome measure, presence of the major allele G, which is also the RA susceptibility allele, at the PTPRC locus (rs10919563) was associated with an improved response to TNF blockade therapy, as determined under an additive model (regression coefficient 0.19, 95% confidence interval [95% CI] 0.09, 0.37 versus carriers of allele A; P = 0.04) (Table 2). This evidence concerns the gene PTPRC and rheumatoid arthritis.