E2F1 seems to participate in modulating the expression of proangiogenic factors, vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1 subunit alpha (HIF1A), and cell cycle progression genes (CCNE2 and MYBL2), which are critical for synovial hyperplasia in RA [61]. Here, E2F1 is linked to rheumatoid arthritis.