The HTR1B receptor has been linked to mental disorders in humans, and members of the HTR receptor family (1 A, 1B, 2 A) harbor polymorphisms that have been associated with aggressive behavior in dogs [2, 10]; in addition, in humans, HTR1B inactivation reduces anxiety levels, a behavior disorder resulting from a stress event [33]. The gene discussed is HTR1B; the disease is Anxiety.