ATP1A1 and colitis: A number of genes encoding ion transporters were affected by TNBS colitis, including: Atp1a1, encoding the catalytic subunit of the Na+/K+ pump; Scnn1a, encoding the alpha polypeptide of the epithelial sodium channel; Nhe1, encoding the housekeeping Na+/H+ exchanger; and Slc12a2, encoding Nkcc2, the Na+/K+/Cl- cotransporter.