ERBB2 and neoplasm: Trastuzumab inhibits mitogen-activated protein kinases and phosphatidylinositol-4, 5-bisphosphate 3-kinase/protein kinase B pathways, leading to the suppression of cell growth and proliferation, triggering of ERBB2 degradation through tyrosine kinase-ubiquitin ligase activity, and attraction of immune cells to ERBB2 overexpressing tumour sites through antibody-dependent cellular cytotoxicity (ADCC) [14].