After MI, sympathetic nerves involved in cardiac innervation are damaged, and various local and circulating neurotrophic factors, for instance, GAP43 (growth-related protein 43) and NGF (nerve growth factor), participate in the repair process, resulting in excessive nerve sheath cells and axon regeneration around the infarcted tissue [3, 4]. The gene discussed is NGF; the disease is myocardial infarction.