Cemiplimab was approved in 2021 in the United States as a first-line monotherapy for treatment of patients with metastatic or locally advanced non-small cell lung cancer (NSCLC) who are not candidates for surgical resection or definitive chemoradiation, and whose tumors have high programmed cell death-ligand 1 (PD-L1) expression (tumor proportion score ≥50%) with no epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), or c-ros oncogene 1 (ROS1) genomic aberrations (1–3). The gene discussed is ALK; the disease is neoplasm.