On the other hand, GHSR1a, because of the “promiscuity” of its interactions with a variety of neurotransmitter receptors (protomers) and signaling pathways, offers more than any other protomer the unique possibility of fine-tuning specific protomer partners in region-specific heteromers involved in the modulation of depression and anxiety with a reduced side-effect profile. This evidence concerns the gene GHSR and major depressive disorder.