SIRT1 and rheumatoid arthritis: Summarizing, this study shows cilostazol activates SIRT1, and thus, elicits dual effects in RA SFs, that is, (1) it inhibits NF-κB-mediated transcription, which suggests the suppressions of HIF-1α and VEGF, and (2) it increases HIF-1α deacetylation by enhancing SIRT1 activity, which further blocks VEGF expression and leads to the inhibition of synovial angiogenesis.