Putative organic anion antiporter with apparent broad substrate specificity. Recognizes various substrates including thyroid hormone L-thyroxine, prostanoids such as prostaglandin E1 and E2, bile acids such as taurocholate, glycolate and glycochenodeoxycholate and peptide hormones such as L-arginine vasopressin, likely operating in a tissue-specific manner (PubMed:10873595, PubMed:14631946, PubMed:16971491, PubMed:19129463, PubMed:30063921). The transport mechanism, its electrogenicity and potential tissue-specific counterions remain to be elucidated (Probable).