These mice display a multitude of abnormalities in their physiological makeup including response to stress with elevated levels of corticosterone, adrenocorticotropic hormone, and epinephrine32, 48, 49 as well as in their behavioral phenotype including increased anxiety, acoustic startle, and learned helplessness32 which are consistent with observations made in human carriers of the short 5′ HTTLPR allele. Here, POMC is linked to Anxiety.