PIM1 and rheumatoid arthritis: Considering the potentially confounding influence of age, swollen or tender joint count, and, in particular, acute phase response (Table 1 and supplementary Tables S1 and S3, available at Rheumatology online), we used logistic regression to confirm that the up-regulation of BCL3, PIM1 and SOCS3 observed in early RA was independent of these clinical parameters (P < 0.05 for each gene; Table 3).