So in a galactose, it points up, in glucose, it points downwards. So this is in fact an example of a glucose. So we go from UDP galactose to UDP glucose by the activity of UDP galactose for epimerase. And so epimerase, or epimerase, is basically an enzyme that transforms one epimer into a different epimer. Now, the point of step three was to basically regenerate this molecule here. And so now if we sum up all these three steps, because this molecule, UDP glucose was regenerated here, these will simply cancel out.