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. And so if we sum these up, this is the net equation after three steps. So after three steps of this pathway, galactose plus ATP gives us glucose one phosphate plus ADP plus H. Now, what is the final step? Because we still haven't formed a molecule that we wanted, so we wanted to form a glucose six phosphate.