Acetone acetate is reduced into this product by using NADH inside our liver. Now, what determines the concentration at equilibrium of these two molecules? So do we have more of aceto acetate, or do we have more of this product? Well, the answer to that lies to the ratio of NADH to NAD plus. High levels of NADH, or high ratio of NADH to NAD plus basically means we have way more reactants, and that will drive the reaction forward. And so high levels of NADH or high ratio of NADH to NAD plus basically means we'll have many D three hydroxybutyrate molecules compared to aceto acetate.