Mediates potential-dependent transport of a variety of organic cations. May play a significant role in the disposition of cationic neurotoxins and neurotransmitters in the brain. Expressed in placenta, skeletal muscle, prostate, aorta, liver, fetal lung, salivary gland, adrenal gland, kidney and brain cortex. No expression detected in spleen. Belongs to the major facilitator (TC 2.A.1) superfamily. Organic cation transporter (TC 2.A.1.19) family.