PIAS1 and atherosclerosis: In this study, it is determined that homocysteine (Hcy) downregulates the expression of circ‐PIAS1‐5 by global circRNA expression profiling and that circ‐PIAS1‐5 inhibits Hcy‐mediated lipid accumulation in foam cells and the pathogenesis of atherosclerosis by acting as a sponge for miR‐219a‐2‐3p.