Choline transporter (By similarity). Essential for hair cell survival. Interacts with COCH. Expressed at high levels in lung, colon and in supporting cells of the inner ear (at protein level). Progressively lower levels in brain, tongue, liver and kidney (at protein level). In the tongue, strongly expressed in epithelial cells and in nerves within the musculature. Within the nerves, expression observed in the perineurial cells of the nerve sheath, in the Schwann cells and myelinated nerve fibers (at protein level). In the kidney, prominent expression in glomeruli in the lining of Bowman's capsule and on the mesangial cells adjacent to the vessels within the glomerulus (at protein level). Strongly expressed on the membranes of splenocytes (at protein level). N-glycosylated; contains sialic acid. Not O-glycosylated. Antibody KHRI-3, which is directed against a N-linked carbohydrate of CTL2, causes hearing loss when infused in the organ of Corti. Belongs to the CTL (choline transporter-like) family.