ERBB2, also known as receptor tyrosine-protein kinase erbB-2 isoform, belongs to the epidermal growth factor (EGF) receptor family. It is an oncogene encoding a type 1 tyrosine kinase growth factor receptor. Its overexpression is associated with reduced disease free and overall survival. It is a predictor factor for poor response to chemotherapy and plays a key role in development, cell proliferation and differentiation. It is permanently coupled to phospholipase C gamma and involves tyrosine phosphorylation and activation of PLC gamma. It reflects the molecular biological properties of gastric cancer and may be clinically used to determine indications for the use of targeted drugs. It results in cellular transformation and is associated with a variety of malignancy and breast, prostate, ovarian, lung cancers. Recombinant human ERBB2, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.