Utilizing our proteogenomic resources from a cohort of 262 iCCA patients （Cancer Cell. 40(1):70-87 e15）, we identified ST3GAL1 as a prognostically relevant molecule in iCCA. Moreover, overexpression of ST3GAL1 promoted proliferation, migration and invasion and inhibited apoptosis of iCCA cells in vitro. We identified the proteins and the O-glycosylation that ST3GAL1 may regulate and identified downstream pathways through proteomic and glycoproteomic analysis