5MPN is a first-in-class, potent, orally active and selective 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 4 (PFKFB4) inhibitor. 5MPN appears to be a competitive inhibitor of the F6P binding site (Ki=8.6 μM). 5MPN does not inhibit PFK-1 or PFKFB3. 5MPN targets the sugar metabolism of tumors and suppresses proliferation of multiple human cancer cell lines.