Abstract: The organic anion transporter (OAT) subfamily is an important part of the SLC22(solute carrier 22) transporter family. OATs are expressed in many tissues, including liver, kidney, brain, placenta and so on. A great deal of attention has been paid to OAT because of its role in handling of common drugs (antibiotics, antivirals, diuretics, nonsteroidal anti-inflammatory drugs), toxins and nutrients. Data from recent metabolomics, microarray and system biology studies, phenotypes of Oat1 and Oat3 knockouts, indicate a central role of this pathway in the metabolism as well as putative uremic toxins of kidney disease. The expressions of certain OATs in conjunction with phase I and phase II drug metabolizing enzymes are regulated by nuclear receptors and other transcription factors. According to the "remote sensing and signaling hypothesis", some OATs have a strong relationship with certain particular signaling molecules. OATs may play a role in remote inter-organ communication via regulating levels of signaling molecules and key metabolites in tissues and body fluids. OATs play a significant role in the transportation of internal and external material under normal and pathological conditions.