– Fructose-2,6-biphosphatase 3, also known as 6-phosphofructo-2-kinase or PFK2 or PFKFB3, involved in both the synthesis and degradation of fructose-2,6-bisphosphate, a regulatory molecule that controls the activity of the enzymes phosphofructokinase 1 (PFK-1) and fructose 1,6-bisphosphatase (FBPase-1) to regulate glycolysis and gluconeogenesis. Highly phosphorylated PFKFB3 protein was found in human tumor cells, vascular endothelial cells, and smooth muscle cells. Because of its proto-oncogenic character, the PFK-2/FBPase-2 of the PFKFB3 gene is assumed to play a critical role in tumorigenesis. PFKFB3 also plays a crucial role in the progression of cancerous cells by enabling their glycolytic pathways even under severe hypoxic conditions, which makes it a potential target for cancer therapy.