This gene encodes a liver-specific member of the organic anion transporter family. The encoded protein is a transmembrane receptor that mediates the sodium-independent uptake of endogenous and xenobiotic compounds and plays a critical role in bile acid and bilirubin transport. Mutations in this gene are a cause of Rotor type hyperbilirubinemia. Alternative splicing of this gene and the use of alternative promoters results in transcript variants encoding different isoforms that differ in their tissue specificity. [provided by RefSeq, Mar 2017].