Immune checkpoint inhibitors (ICIs) that target programmed cell death protein 1 (PD-1) or its ligand (PD-L1) are a class of cancer immunotherapy that are widely used to treat a range of cancers, including advanced non-small cell lung cancer (aNSCLC).1 Treatment with ICI therapy for PD-L1-high (>50%) NSCLC improves clinical outcomes compared to chemotherapy.2 However, because ICI agents modify the activity of immune cells through the PD-1/PD-L1 pathway, they are associated with immune-related adverse events (irAEs) that can affect multiple organ systems. The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.