Risk factors for ICI cardiotoxicity remain poorly defined, but combination therapy, pre-existing autoimmune disease, and anti-CTLA-4 use are proposed.10,11 Treatment typically involves high-dose glucocorticoids, with immunosuppressants (e.g. mycophenolate mofetil,12 alemtuzumab13) for steroid-refractory cases. Here, CTLA4 is linked to autoimmune disease.