As HAS2 is a critical enzyme involved in atherosclerosis with vessel thickening and its transcription is regulated by NF-κB (46), this study investigated whether HAS2 expression could be regulated by SIRT1 in human aortic smooth muscle cells and whether SIRT1 could control pro-atherogenic behavior of AoSMCs after TNFα proinflammatory treatments. This evidence concerns the gene TNF and atherosclerosis.