May act as a transporter of organic cations based on a proton efflux antiport mechanism. May play a role in the transport of chloroquine and quinidine-related compounds in kidney. Interacts with RNF167. Localized at the apical membrane surface of renal proximal tubules. Expressed at high levels in adult and fetal kidney and liver, and adult colon. Expressed in fetal renal proximal tubules (at protein level). Expressed at lower levels in heart, brain and lung. The gene represented in this entry may be involved in disease pathogenesis. The disease may be caused by variants affecting the gene represented in this entry. Belongs to the major facilitator (TC 2.A.1) superfamily. Organic cation transporter (TC 2.A.1.19) family. It is uncertain whether Met-1 or Met-17 is the initiator.