CTLA4 and non-small cell lung carcinoma: Immune checkpoint inhibitors (ICIs), consisting of T-lymphocyte antigen 4 (CTLA-4) inhibitor and programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) inhibitor, have attracted considerable attention because of their specific antitumor activity that has contributed to the prolonged survival of patients with multiple cancers (Ferris et al., 2016; Escudier et al., 2017; Wolchok et al., 2017; Wu et al., 2019), including those with non-small cell lung cancer (NSCLC).