Retrospective small-series studies depict the clinical features of patients with HER2 MUT NSCLC: younger (middle age around 60 years), female sex, adenocarcinoma histology, light or never-smokers, and generally mutually exclusive of other molecular drivers [12,13,14,15,16,17,18,19]. The gene discussed is ERBB2; the disease is non-small cell lung carcinoma.