Immune checkpoint inhibitors (ICIs) including programmed death-ligand 1 (PD-L1)/programmed death-1 (PD-1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) have been used for different histologic types of cancer including primary lung cancer that represents the most common and fatal cancer globally. Here, CTLA4 is linked to lung carcinoma.