CTLA4 and non-small cell lung carcinoma: Within the last decade, immune checkpoint inhibitors (ICIs) targeting programmed cell death 1 (PD-1), programmed cell death receptor ligand 1 (PD-L1) or cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) have reshaped the treatment landscape for metastatic non-small cell lung cancer (NSCLC) patients2.