Noteworthy, clinical studies in humans seem to indicate a U-shaped relationship between PRL levels and cardiometabolic risk, as both hyper- and hypoprolactinemia have been associated with various metabolic complications, including obesity, impaired glyco-insulinemic and lipid profiles, and metabolic syndrome (MetS) [38, 51, 62, 63]. The gene discussed is PRL; the disease is obesity disorder.