ERBB2 and adenocarcinoma: The data from the aforementioned studies, as well as that from the present study, are contrary to the data of Stephen et al, which showed that mutations in the tyrosine kinase domain of the HER2 gene (different HER2 mutations and abnormalities) are observed in up to 4% of patients with NSCLC (120 primary NSCLC tumors tested), of which, 10% of patients had adenocarcinomas (8).