In the established genetic mice model (Ctla4+/−Pdcd1−/−) of myocarditis, an expansion of CCR2+ macrophages was seen with high expression of CXCL9 and CXCL10 among other pro-inflammatory factors, whereas a similar expanded macrophage population was observed in myocardial tissues of patients with ICI myocarditis as well [79]. Here, CTLA4 is linked to myocarditis.