PFKFB4 and cancer: PFKFB has four subtypes, namely, PFKFB1, PFKFB2, PFKFB3, and PFKFB4, of which PFKFB3 exhibits apical kinase activity and is overexpressed under various signals such as hypoxia, estrogen receptor, RAS activation, and P53 deletion in cancer, which promotes glycolysis flux in cancer metabolism (83, 85–87).