There is increasing evidencethat there is a deficiency of NGF in diabetes, as well as thedependent neuropeptides substance P (SP) and calcitoningene-related peptide (CGRP) that may also contribute tothe clinical symptoms resulting from small fiber dysfunction.Similarly, NT3 appears to be important for large fiberand IGFs for autonomic neuropathy. The gene discussed is TAC1; the disease is autonomic neuropathy.