SLCO2B1 and colon carcinoma: It is shown that HAR is a substrate for the absorption transporter organic cation transporters (OCTs/OCTNs) and organic anion transporting polypeptides (OATPs) in human colon carcinoma and Madin-Darby canine kidney cells [32], and MEM is a substrate for the absorption transporter OCT2 and OATP2B1 in Madin-Darby canine kidney and human embryonic kidney cells [33,41].