Moreover, 13 nm GNPs have antiangiogenic effects due to their ability to bind to important angiogenic factors such as VEGF, both VEGF165 and VEGF121, and basic fibroblast growth factor (bFGF) in RA synovial fluid (SF), which could inhibit RA SF-induced endothelial cell migration and proliferation [198]. Here, FGF2 is linked to rheumatoid arthritis.