ABCB1 and cholangiocarcinoma: In particular, cultured CCA cells (QBC939) exposed to Wnt3a develop an increased resistance to several chemotherapeutic drugs, including 5-FU, cis-diammineplatinum, vincristine and mitomycin C. This effect was not mediated by the activation of the conventional pathways operating in chemoresistance (PI3K/Akt and NF-κB), but by the nuclear translocation of β-catenin, which is associated with the upregulation of ABCB1/P-glycoprotein [148,149].