In the early stage of myocardial infarction, macrophages often polarize into M1 type and perform local inflammatory response by releasing various proinflammatory cytokines such as IL-1β, IL-6, TNF-α and iNOS to clear necrotic myocardial cells, while in the late stage of myocardial infarction, M2 macrophages produce IL-10 and ARG1 to inhibit inflammatory response and promote the repair of cardiac tissue (Cheng and Rong, 2018). Here, ARG1 is linked to myocardial infarction.