PIAS1 and atherosclerosis: To further determine the physiological role of circ‐PIAS1‐5 in atherosclerosis induced by Hcy, circ‐PIAS1‐5‐overexpressing adeno‐associated virus (AAV‐circ‐PIAS1‐5) or a mock vector with no circ‐PIAS1‐5 sequence (AAV‐circ‐NC) was injected into ApoE−/− mice fed a high‐methionine diet at 13 weeks (Figure 4A).