For patients with advanced NSCLC, first-line systemic treatment generally consists of targeted therapy, immunotherapy, cytotoxic chemotherapy, or a chemo-immunotherapy combination depending on the tumor's expression of programmed death-ligand 1 (PD-L1), histology type (squamous versus nonsquamous) and the presence of driver mutations, such as epidermal growth factor receptor (EGFR) activation mutation and anaplastic lymphoma kinase (ALK) translocation. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.