Recombinant human epidermal growth factor (EGF), one of human growth factors, is a 6.2 kda protein containing 53 amino acid residues. EGF is a highly efficient cell division factor with many other biological effects, which mainly includes: 1. stimulating the growth and proliferation of skin, cornea and racheal epithelium tissue in vivo. 2. accelerating the healing process of epidermis damage on skin, cornea, etc. 3. repressing the gastric acid excretion. 4. accelerating the proliferation of epithelial cells in human and animals. 5. facilitating the biosynthesis of protein, rna, dna as well as metabolic activity in epidermal cells.