Heregulin-β 1 also known as neuregulin-1 （NRG-1） is a member of the epidermal growth factor （EGF） family of growth factors and acts as a ligand for ErbB family receptor tyrosine kinases. And NRG1 isoforms can signal in a paracrine, autocrine, or juxtacrine manner, playing a fundamental role during the development of the peripheral nervous system and during the process of nerve repair, suggesting that the treatment with NRG1 could improve functional outcome following injury. The NRG1 receptors are membrane-spanning receptor tyrosin kinases of the ErbB family （ErbB1–4）, of which the EGF receptor （ErbB1） is the most prominent representative.