SLC26A3 and adenoma: So far, two apical chloride/bicarbonate (Cl−/HCO3−) exchangers PAT1 (putative anion transporter 1, Slc26a6) and DRA (downregulated in adenoma, Slc26a3) have been shown to be involved in the secretion (Freel et al., 2006; Jiang et al., 2006) and absorption of oxalate, respectively (Freel et al., 2013).