O-linked N-acetylglucosamine (O-GlcNAc) is a dynamic modification process jointly controlled by the “writer” O-GlcNAc transferase (OGT) and “eraser” O-GlcNAcase (OGA), and an increase in total O-GlcNAc correlates with advanced malignant HCC phenotypes. The gene discussed is OGA; the disease is hepatocellular carcinoma.