The receipt of combination ICI therapy (e.g., a CTLA-4 inhibitor combined with a PD-1 inhibitor) is the most well-established risk factor for the development of ICI myocarditis, with the combination of nivolumab and ipilimumab carrying a 4.74-fold risk of myocarditis compared to nivolumab alone [253]. This evidence concerns the gene CTLA4 and myocarditis.