CTLA4 and cancer: The subsequent and more extensive sections are focused on strategies which may improve the efficacy of anti-cancer immune checkpoint inhibitor therapy, followed by overviews, firstly of putative mechanisms of immunopathogenesis of IRAEs, most prominently CTLA-4 blockade-associated enterocolitis and, finally, strategies, both recognized and proposed, which may enable early identification of those patients with advanced cancer who may be at highest risk for development of IRAEs.