CDC42 and rheumatoid arthritis: According to our present study, in treating RA, umbelliferone and scopoletin 1) exert high binding affinities towards membrane proteins of RA-FLSs, 2) directly target TKs (mostly membrane-bound) and proteins with close interaction with TKs, 3) inhibit NF-κB signaling in RA-FLSs, and 4) attenuate RA-FLS activities (Figures 2–5).