MYC and hepatocellular carcinoma: WT KAT5 increased c-Myc, MMP9, MMP14 expression and promoted cell invasion and migration, whereas the S119A mutant failed to exert this stimulatory role on tumor metastasis (Fig. 5j and Supplementary Fig. 4c, d), suggesting that O-GlcNAcylation plays an essential role in KAT5 activation, resulting in c-Myc accumulation and HCC invasive phenotype.