PDCD1 and non-small cell lung carcinoma: A prospective study of NSCLC patients treated with programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) blockade with or without anti–cytotoxic T-lymphocyte antigen 4 (CTLA4) included 255 patients with BrMs, of which 39.2% were active, 14.3% were symptomatic, and 27.4% were treated with steroids, demonstrating an intracranial ORR of 27.3% in the active BrMs [124].