5-HT2B (5-hydroxytryptamine receptor 2B) is a receptor for serotonin. It is expressed in many peripheral and central nervous system tissues, including stomach fundus, liver kidney, muscle, intestine and brain. 5-HT2B receptors are responsible for many cardiovascular and central nervous system functions, such as blood vessel contraction, platelet shape changes, neuronal sensitization to tactile stimuli, and mediation of the hallucinogenic effects of phenylisopropylamin hallucinogens. It has also been shown to be required for heart development. The cDNA expressed in the cell line has identical sequence to GenBank NM_000867 except for one base pair mutation that results in a change in amino acid at position 477 (from glutamic acid to glutamine). This has been reported as a natural variant.