RBE (human cholangiocarcinoma cell line, ATCC), and PLC (human hepatocarcinoma cell line, ATCC) were maintained as specified by ATCC protocols. RBE cells were cultured in RPMI 1640 (Gibco, Carlsbad, USA) while PLC was routinely maintained in DMEM medium (Gibco). These cell lines were supplemented with 10% fetal bovine serum (FBS, Gibco) and penicillin-streptomycin (100 units/ml) in 5% CO2 at 37 °C.