Hcy enrichment of circ‐PIAS1‐5 leads to YTHDC1 binding to circ‐PIAS1‐5 and promotes its intracellular localization from the nucleus to the cytoplasm, which contributes to circ‐PIAS1‐5 acting as a sponge of miR‐219a‐5p to promote lipid accumulation in foam cells in Hcy‐induced atherosclerosis through regulating TEAD1. The gene discussed is PIAS1; the disease is atherosclerosis.