SLC22A5 and renal fibrosis: In addition, since reabsorption of carnitine from urine into the cytoplasm is mediated by Organic Cation Carnitine Transporter 2 (OCTN2) in the proximal tubular epithelium [27], it is possible that inhibition of OCTN2 activity by TAC may cause carnitine depletion, tubular damage, and renal fibrosis.