ERBB2 and lip and oral cavity carcinoma: Genetic profiling of oral cancer samples has demonstrated this hyper-responsiveness through recurrent focal amplifications in EGFR and ERBB2 genes, respectively, encoding for receptor tyrosine kinases (RTKs) epidermal growth factor receptor (EGFR) and erythroblastic oncogene B 2 (ERBB2, alternatively known as human epidermal growth factor receptor 2; HER2) which respond to mitogenic ligands [67].