Platinum-doublet chemotherapy (±bevacizumab) has remained the main first-line therapy for patients with metastatic NSCLC for a long time until immune checkpoint inhibitor (ICI) comes out (Sandler et al., 2006; Zhou et al., 2015; Planchard et al., 2018), such as inhibitors of programmed death 1 (PD-1) and its ligand PD-L1, which are effective therapies for metastatic NSCLC lacking sensitizing epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) mutations (EGFRm or ALKm). The gene discussed is EGFR; the disease is non-small cell lung carcinoma.