FGF2 and rheumatoid arthritis: Taken together with Figs. 1 and 2, these results imply that bFGF and its downstream FGFR3/RSK2 signaling axis might play pivotal roles in the proliferation and migration of RA FLSs and persistent inflammation in RA joints, which suggests the rationale for FGFR3/RSK2 signaling targeting in RA to inhibit the development and progression of RA.