MiR-503-5p promoted proinflammatory cytokines and adhesion molecules level and atherosclerosis development by regulating smad family members 1 (smurf1), 2 (smurf2), and 7 (Smad7) in RAW264.7 macrophage-derived foam cells and apoE-/- mice 179, suggesting that circ-HMGCS1 may suppress proinflammatory cytokines by regulating miR-503-5p/smurf1, smurf2, Smad7 axis. The gene discussed is SMURF2; the disease is atherosclerosis.