ARG1 and Myocardial fibrosis: From 3 to 7 days (middle and late stage), M2 macrophages are the primary type, and type 2 predominantly secretes arg-1, TGF-β, etc., which mainly promote angiogenesis and degradation of extracellular matrix, stimulate fibroblasts into myofibroblast differentiation, participate in the occurrence of myocardial fibrosis [36, 37], and participate in anti-inflammatory and tissue repair [38,39].