Several transporters which are related to cholestasis have been identified in hepatocytes, such as multidrug resistance protein (Mdr), bile salt export pump (Bsep), multidrug resistance associated protein (Mrp)[8,9], organic solute transporter alpha/beta (Ostα/β)[10], Na+ taurocholate cotransporting polypeptide (Ntcp)[9], and organic anion transporting polypeptide (Oatp)[11]. The gene discussed is SLCO1A2; the disease is cholestasis.