HER3 (Human epidermal growth factor receptor 3), also referred to ERBB3, ErbB-3, LCCS2, Erb-b2 receptor tyrosine kinase 3 or receptor tyrosine-protein kinase erbB-3, is a membrane-bound protein with a neuregulin binding domain (not an active kinase domain). It is encoded by the human ERBB3 gene mapping at the chromosome 12q13.2. HER3 acts as a cell surface receptor for neuregulins and belongs to the epidermal growth factor receptor (EGFR/ERBB) family of receptor tyrosine kinase. Regulation of HER3 expressions and signal transductions involve many interacting proteins, including PI3K, Shc, Nrdp1, and E3 ubiquitin ligases NEDD4. Overexpression of this gene has been reported in various cancers, such as bladder, prostate, and breast tumors. This receptor is emerging as a molecule target for increasing cancers. IGFR (Insulin-like growth factor receptor) is a protein discovered on the surface of several types of cells binding to IGF (Insulin-like growth factor). IGFR is observed at high levels on the surface of certain cancer cells, which leads these cells to growing rapidly in the presence of IGF. IGFR comprises two receptors that are IGF-1R (Insulin-like growth factor 1 receptor) and IGF-2R (Insulin-like growth factor 2 receptor). The gene of IGF-1R is located on chromosome 15q26.3 and encodes a tyrosine kinase receptor with a high-affinity for IGF. This receptor plays an essential part in transformation events of cell growth and survival. IGF-1R is over-expressed in cancer where it has anti-apoptotic activity and can enhance the malignant cell survival. IGF-2R consists of a single binding unit and its phosphorylation in whole cells is less IGF-dependent.