CD40 and rheumatoid arthritis: Notably, the MFI of CD40 was highest on naive B cells, which indicates that the activation of B cells is a common phenomenon in RA.Longitudinal analysis of our cohort revealed that these cytological changes persisted during the 2-year follow-up, although the inhibitory effect of JAKis on B-cell immune responses still needs to be further clarified as soon as the drug is removed.