CTLA4 and non-small cell lung carcinoma: The ARCTIC sub-study was conducted as part of the phase III ARCTIC clinical trial in patients with advanced NSCLC treated with durvalumab, a programmed cell death ligand 1 (PD-L1) antibody, and tremelimumab, an anti-cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) [11, 12].