Sodium-independent organic anion transporter, exhibits high specificity for sulfated conjugates of xenobiotics and steroid hormones such as estrone 3-sulfate (E1S) and dehydroepiandrosterone sulfate (DHEAS) (PubMed:17393504, PubMed:26239079, PubMed:28945155). Can transport the statin pravastatin and may contribute to its disposition into the hepatocytes when the function of OATPs is compromised (PubMed:26239079). It is specifically activated by 3 to 5 carbons-containing short-chain fatty acids/SCFAs, including propionate (propanoate), butyrate (butanoate) and valerate (pentanoate) (PubMed:17393504). May operate the exchange of sulfated organic components against short-chain fatty acids/SCFAs, in particular butanoate, at the sinusoidal membrane of hepatocytes (PubMed:17393504).