ERBB2 and lung adenocarcinoma: Aberrations in human epidermal growth factor receptor 2 (HER-2, ERBB2) have emerged as oncogenic drivers and therapeutic targets in 1–4% of non-small cell lung cancer (NSCLC) and up to 6% of EGFR/KRAS/ALK-negative lung adenocarcinoma (LUAD) (1, 2).