PFKFB3 and cancer: Furthermore, the limited glucose supply notably decreased the hypoxia-induced PFKFB3 O-GlcNAcylation in both cancer (SW1990) and normal (HPDE) cells, but still remained at a comparable level in cancer cells due to the aberrant OGT activity (Fig. 1e), which is in line with the global cellular O-GlcNAcylation according to our study (Fig. S1b) and previous report3,4,21,22.