ERBB2 and colonic neoplasm: Receptor tyrosine kinases (RTKs), such as epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2) and endothelial growth factor receptor (VEGFR), and the downstream mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Akt pathways are often de-regulated in multiple solid tumors, e.g. breast, lung, bladder and colon cancer.