Given that several studies have described CD8+ cytotoxic T cell infiltration in the myocardium of patients with ICI myocarditis [5,18], it would be expected that IFN-γ is involved given that the differentiation of naïve CD8+ T cells into cytotoxic T cells requires IFN-γ [19,20]. The gene discussed is IFNG; the disease is myocarditis.