Immune checkpoint inhibitors (ICIs) are considered one of the most important breakthroughs in non-small cell lung cancer (NSCLC) treatment considering the impressive efficacy and durable activity achievable in a proportion of patients with programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) inhibitors [1]. The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.