The enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB or PFK-2) has been reported to be overexpressed in most tumor cells under hypoxic conditions [37], where it is responsible for maintaining cellular levels of fructose-2,6-bisphosphate (F-2,6-BP) by synthesizing or degrading fructose-2,6-bisphosphate. This evidence concerns the gene PFKFB3 and neoplasm.