Mediates electroneutral potassium-chloride cotransport when activated by cell swelling. May mediate K(+) uptake into Deiters' cells in the cochlea and contribute to K(+) recycling in the inner ear. Important for the survival of cochlear outer and inner hair cells and the maintenance of the organ of Corti. May be required for basolateral Cl(-) extrusion in the kidney and contribute to renal acidification (By similarity). Inhibited by WNK3. Homomultimer and heteromultimer with other K-Cl cotransporters. Widely expressed with highest levels in kidney, liver and pancreas. Expressed in choroid plexus and suprachiasmatic nucleus. Belongs to the SLC12A transporter family. Intron retention. This sequence is incomplete at its 3'end and extensively differs from that shown in positions 214-251.