C: chemotherapy with cytotoxic agent, CI: combination systemic anticancer treatments with cytotoxic agents and immune checkpoint inhibitor, I: immune checkpoint inhibitor, M: molecular targeting agent, Ad: adenocarcinoma, Sq: squamous cell carcinoma, NOS: not otherwise specified, Post op: postoperative recurrence, EGFR: epidermal growth factor receptor, ALK: anaplastic lymphoma kinase, KRAS: Kirsten rat sarcoma viral oncogene homolog, MET: mesenchymal–epithelial transition factor, ROS1: ROS proto-oncogene 1, BRAF: B-Raf proto-oncogene, NE: not evaluated. The gene discussed is KRAS; the disease is squamous cell carcinoma.