SERT (Serotonin Transporter) is a transmembrane transporter protein that belongs to the monoamine transporter family. It consists of 12 transmembrane domains and is located on the cell membranes of neurons and platelets. SERT is responsible for reuptaking serotonin (5-HT) from the synaptic cleft into presynaptic neurons, thereby terminating the signal transmission of 5-HT and regulating its reuptake. SERT is involved in regulating emotions, sleep, appetite, and pain perception, among other physiological processes. The expression of the SERT gene (SLC6A4) is tissue-specific, and its polymorphisms are associated with various psychiatric disorders, including depression, anxiety disorders, and obsessive-compulsive disorder.