HIF1A and rheumatoid arthritis: This study aims to evaluate the therapeutic efficacy of emodin (EMO) in rheumatoid arthritis (RA) and to verify whether its underlying mechanism involves the blockade of pathological angiogenesis via the inhibition of the nuclear factor-kappa B (NF-κB)/hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) signaling axis.