Thus, it is necessary for human liver to export excessive bile acid so as to maintain its benign circulation. ABCB11 is an important bile acid transporter, but its transport mechanism remains unclear.

Background and Aim:Progressive familial intrahepatic cholestasis type 2 (PFIC2) results from genetic defects of the hepatobiliary bile salt export pump (BSEP, ABCB11) at chromosome 2q24.