In synovial fluid‐derived SFs, Cav‐1 mediates the expression of C–C chemokine ligand 2/monocyte chemoattractant protein‐1 [62], which then promotes monocyte migration into the joint cavity, differentiation into macrophages, and the development of RA synovitis through the production of pro‐inflammatory cytokines and other mediators [63]. The gene discussed is CAV1; the disease is rheumatoid arthritis.