Additionally, polymorphism of the short allele of SLC6A4 which encodes the SERT has been associated with obesity (Sookoian et al. 2007), and molecular imaging has supported the role of genetics in 5-HT regulation by reporting higher SERT binding in homozygotic carriers of the two long alleles of the SERT within the midbrain (Reimold et al. 2007). Here, SLC6A4 is linked to obesity disorder.