a, b, GSEA (a) and heatmap (b) of hepatocyte protein expression in ICC cell lines according to SULT1A1 protein levels. Significance was calculated as false discovery rate by the GSEA package. Q < 0.25 was considered statistically significant. c, Circos plot of 28 biliary tract cell lines depicting YC-1 sensitivity, biliary cancer type, and specific molecular features (i.e., IDH1 mutation, FGFR2 fusion, and absence of BAP1 protein expression). Asterisk indicates mixed ICC/HCC histology. ECC, extrahepatic cholangiocarcinoma; GB, gallbladder carcinoma; N.D., normal duct. d, YC-1 sensitivity measurement in representative HCC, ECC, and GB cell lines. Two biologically independent experiments are shown. e, Scatter plot comparing YC-1 IC50s of cell lines between liver cancer subtypes. Asterisks indicate cell lines exhibiting no response to YC-1 (IC50 not calculable). f, Model relating SULT1A1 expression, liver lineage marker expression, and genomic alterations in ICC.