Epidermal growth factor
It is a critical autocrine growth factor as well as a mitogen for astrocytes, Schwann cells, and fibroblasts. It is ligand for epidermal growth factor (EGF) and it is related to transforming growth factor alpha (TGF-alpha). This protein interacts with the Epidermal growth factor receptor (EGFR) to promote the growth of normal epithelial cells.