Introduction: Nerve growth factor (NGF), is a small secreted protein which induces the differentiation and survival of particular target neurons (nerve cells). NGF is a protein that consists of 3 types of polypeptide chains -- alpha, beta and gamma -- that interact to form the protein. The NGF beta chain (NGFB) is solely responsible for the nerve growth stimulating activity of NGF. The NGFB gene is in chromosome band 1p22. An ointment containing NGF has been reported to help heal bedsores. NGF i