EGR1 and rheumatoid arthritis: Over-expression of EGR-1 in RA synovial fibroblasts may promote synovial fibrosis in RA by activating genes encoding α1 and α2 chains of type I collagen, and at the same time, it can regulate the production of proinflammatory factors through synergistic mechanisms and other pathways [34,35,36,37] (Figure 6B).