Masson and Sirius red staining showed that anti‐CTLA‐4 m2a antibody further exacerbated myocardial fibrosis and collagen deposition in the myocardium of EAM mice compared with anti‐IgG antibody‐treated EAM mice (Figure 1g,h). This evidence concerns the gene CTLA4 and Myocardial fibrosis.