HER2 (Human epidermal growth factor receptor 2), also known as ERBB2, CD340 (cluster of differentiation 340), proto-oncogene Neu, is a membrane tyrosine kinase and has strongest catalytic kinase activity in HER family. Among four HER family proteins, HER2 functions as the most active signaling complex after dimerization with other members. It is encoded by the oncogene ERBB2, which is located at the human chromosome 17q12. HER2 participates in normal cell growth and found on some types of cancer cells. Its amplification is the major pathway causing HER2 receptor overexpression. HER2 is amplified in approximately 15%-20% of breast cancers and functions as the primary driver in breast tumor development and progression. The overexpressed HER2 is regarded as a valuable target in clinic therapeutics. MET, also known as c-MET or HGFR (Hepatocyte growth factor receptor), is a transmembrane tyrosine kinase receptor that is encoded in humans by the MET gene. This receptor in charge of tyrosine-kinase activity is mapped at the chromosome 7q31.2 with 1408 amino acids. MET and its ligand HGF/SF (Hepatocyte growth factor/Scatter factor) are expressed in many tissues, principally in epithelial and mesenchymal origin cells, respectively. After binding to ligands, this tyrosine-protein kinase is rapidly internalized, polyubiquitinated and then degraded in a proteasome-dependent manner. MET is over-expressed in numerous types of neoplasms, such as tumors of the kidney, pancreas, thyroid and osteosarcoma. And it is reported that various mutations of MET gene are correlated with papillary renal carcinomas.