Some patients with later stages of NSCLC respond to and benefit from immunotherapy using immune checkpoint inhibitors (ICIs) (e.g., ipilimumab, atezolizumab, nivolumab) to disrupt T-lymphocyte-associated protein 4 (CTLA-4) or programmed cell death protein 1 (PD-1)/programmed cell death protein 1 ligand (PD-L1) pathways, thus reactivating T-cell response to kill tumor cells [3]. The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.