PRTN3 and rheumatoid arthritis: There was no evidence of statistical interaction between smoking status (never, ever) and SE for all RA, ACPA-positive RA, ACPA-negative RA, RF-positive RA, RF-negative RA (p = 0.37, 0.50, 0.24, 0.26, and 0.81 respectively), and the 95% CI for the AP for all interactions included 0.