SLC9A3 and adenoma: Predominantly, in the ileum and proximal colon, NHE3 is part of a transport process called electroneutral NaCl absorption in which NHE3 transport activity occurs in parallel with a brush border Cl−/HCO3− exchanger of the SLC26A family, that is generally believed to be SLC26A3 (Downregulated in Adenoma, DRA) (Zachos et al., 2005; Zachos et al., 2009a; Kiela and Ghishan, 2009; Ghishan and Kiela, 2012; Donowitz et al., 2013).