CD8A and arrhythmogenic right ventricular cardiomyopathy: Inter-group comparisons identified 13 highly infiltrated immune cells in the ARVC myocardium, including activated CD8 T cell, CD4 TCM, MBC, Treg, Th1, Th2, CD56dim NK cell, macrophage, mast cell, MDSC, NKT cell, neutrophil, and PDC; only Th17 and eosinophil were depressed in ARVC (Figure 3A).