CD274 and cholangiocarcinoma: The time-dependent treatment of 5-FU induces AZGP1 secretion and cell death (Fig. S1A-B), and it has also been confirmed that a significant increase of PD-L1 in both the mean fluorescence intensity (MFI) and protein level in the 5-FU-treated CCA cells compared to the control (Fig. S1C-D).