Well, because it regulates the commitment step of glycolysis. So it transforms fructose six phosphate into fructose one six bisphosate. When we're at this stage the fructose six phosphate before it has been transformed, it has a choice. It can either move into the active side of the phosphorinase, in which case it will be transformed into this product, or it can go on to form glycogen. But once we form the fructose 116 bits phosphate, this product has now been committed to the process of glycolysis. So this is the most important enzyme because it essentially tells this molecule to continue and commit to that process of glycolysis.