CTLA4 and neoplasm: The utility of checkpoint inhibitors is being increasingly explored in patients with brain tumors and brain metastases.6,7 Furthermore, multiple clinical trials are exploring the combination of ICIs with radiation therapy and oncolytic viruses to achieve better responses.6,7 Newer molecules inhibiting CTLA-4 or PD-1/PDL-1 are being studied in clinical trials treating multiple tumor types.