PFKFB3 and neoplasm: Indeed, disturbing PFKFB3 function in TECs, both by endothelial-specific genetic loss or by general pharmacological inhibition with the small molecule 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one (3PO), arrested EC sprouting and proliferation [55,96], decreased EC leakiness, tightened the vascular barrier, and restored perfusion, inducing tumor vessel normalization [4,13].