Epidermal growth factor (Epidermal growth factor, EGF) is the earliest discovered growth factor plays an important role in regulating cell growth, proliferation and differentiation. In humans, the epidermal growth factor protein of 53 amino acid residues, 6 one thousand three disulfide bonds, quality ear Dayton. 

     Epidermal growth factor in combination with the cell surface receptor, the epidermal growth factor receptor (EGFR) functions. [3] combined with the high affinity of the epidermal growth factor receptor to stimulate receptor intrinsic tyrosine kinase activity, which initiates a signal transduction cascade and lead to a variety of biochemical changes in intracellular calcium levels rise, increasing the sugar leaven Solutions and protein synthesis, increase in the expression of certain genes (including epidermal growth factor receptor), eventually leading to DNA synthesis and cell proliferation.