CD4 and myocarditis: The histopathologic analysis of myocardial tissue from patients with suspected ICI-associated myocarditis demonstrated typical findings noted in non-ICI myocarditis with a diffuse T cell predominant lymphocytic infiltration in the myocardium with a predominance of CD3+, CD4+, CD8+ T lymphocytes and CD68+ macrophages, occasionally with eosinophils and also myocardial necrosis or fibrosis [28].