The Organic Anion Transporter (OAT) family is a group of transmembrane proteins responsible for the transport of organic anions into and out of cells. The main family members include OAT1 to OAT7, which consist of multiple transmembrane domains and are primarily located on the cell membrane of tissues such as the kidneys, liver, and brain. OAT transporters are involved in regulating the absorption, distribution, and excretion of drugs, endogenous metabolites, and toxins. By affecting the transmembrane transport of these substances, OATs regulate the pharmacological and toxicological responses of cells. The expression of OAT family members is tissue- and cell-specific, and mutations or dysregulation of their genes are associated with various diseases, including drug resistance, metabolic disorders, and toxic injury.