Molecular testing for patients newly diagnosed with non-small-cell lung cancer (NSCLC), including alterations in the genes EGFR, ALK, KRAS, ROS1, BRAF, NTRK, MET, RET, and ERBB2, is routinely performed to detect genetic alterations and thus determine the appropriate targeted therapy. The gene discussed is ERBB2; the disease is non-small cell lung carcinoma.