PFKM is a regulatory glycolytic enzyme that converts fructose 6-phosphate and ATP into fructose 1,6-bisphosphate (through PFK-1), fructose 2,6-bisphosphate (through PFK-2) and ADP. Three phosphofructokinase isozymes exist in humans: muscle, liver and platelet. Mutations in PFKM gene have been related with glycogen storage disease type VII, also identified as Tarui disease.