Ghrelin, an acylated 28-amino-acid peptide hormone, is the endogen ligand for the growth hormone secretagogue receptor [107]; it is produced by the gastrointestinal tract, especially by the stomach, and plays a role in regulating appetite [108]; it is also involved in various metabolic processes, in regulating body weight, and apparently has beneficial implications in cardiovascular diseases. The gene discussed is GHRL; the disease is cardiovascular disorder.