In a retrospective study of data from eight clinical centers by Mahmood et al., of 35 patients who had myocarditis, 12 were receiving combinations of anti-CTLA-4 and anti-PD1/PD-L1, 11 were on pembrolizumab monotherapy and 7 on nivolumab monotherapy [7]. This evidence concerns the gene PDCD1 and myocarditis.