CTLA4 and non-small cell lung carcinoma: Immune checkpoint inhibitors (ICIs) revolutionised the treatment of non-small-cell lung cancer (NSCLC),1 however, aside from PD-L1 expression level, reliable biomarkers to choose between first-line single-agent PD-1/PD-L1 inhibitors (mono-ICI), anti-PD-(L)-1 agents in combination with CTLA-4 inhibitors (combo-ICI) and ICI-platinum-based chemotherapy (PCT) combinations are currently lacking.