ABCB1 and cholangiocarcinoma: This experimental model has contributed to advance in the identification of antitumor drugs that are substrates of the main ABC pumps involved in MOC-1b of HB and HCC, such as multidrug resistance protein 1/P-glycoprotein (MDR1/P-gp) (ABCB1) [7] and MRP2 (ABCC2) [8], and CCA, such as MRP3 (ABCC3) [9].