As such, comprehensive biomarker testing to identify the presence of oncogenic driver alterations (including various EGFR mutations, anaplastic lymphoma kinase (ALK), RET, NTRK 1/2/3, ROS1, BRAF V600E, METex14 skipping and ERBB2) is recommended for patients with advanced/metastatic NSCLC before initiation of first-line treatment, except for patients with KRAS G12C mutation, ERBB2 mutation or EGFR exon 20 insertion mutation, where targeted therapy is recommended as a second-line treatment2,3. The gene discussed is ERBB2; the disease is non-small cell lung carcinoma.