HTR3C belongs to the ligand-gated ion channel receptor superfamily. HTR3E is a subunit E of the type 3 receptor for 5-hydroxytryptamine (serotonin), a biogenic hormone that functions as a neurotransmitter, a hormone, and a mitogen. This receptor causes fast, depolarizing responses in neurons after activation. Genes encoding subunits C, D and E form a cluster on chromosome 3. An alternative splice variant has been described but its full length sequence has not been determined.