Benzyl-α-GalNAc is a potent O-glycosylation inhibitor. Benzyl-α-GalNAc effectively inhibits the proliferation and activation of LX-2 cells and suppresses the expression of collagen I/III, which has good potential for investigation in liver fibrosis. Benzyl-α-GalNAc also significantly enhances the anti-tumour activity of 5-FU (HY-90006) (e.g. pancreatic cancer) by inhibiting O-glycosylation.