NRG-1β/ Heregulin β-1 is a multifunctional growth factor of the neuregulin family that acts as a ligand for members of the ErbB/HER receptor tyrosine kinase family, particularly HER3 (ErbB3) and HER4 (ErbB4). It plays essential roles in cell communication, tissue development, regeneration, and cancer biology. NRG-1β activates signalling pathways involved in cell growth, survival, and differentiation in epithelial, neuronal, cardiac, and glial cells. In addition, it stimulates angiogenesis, at least in part through the upregulation and secretion of vascular endothelial growth factor (VEGF). In cancer biology, NRG-1β has been associated with enhanced motility and invasiveness of breast cancer cells, highlighting its importance in tumor progression and metastatic processes. Furthermore, NRG-1β plays a significant role in tissue regeneration and wound healing, particularly in epidermal repair and peripheral nerve regeneration.