And that allows the fitting, that allows the insertion of that fe atom into that hin group, into that protoporphrine. Now, how can we use this to basically build an antibody with a specific type of catalytic ability? Well, normally, the protoporphrine has a planar shape and we see that what this enzyme does is it basically bends the shape. And so the transition state of the protoporphine ring has to be bent in shape. So the transition state of the protoporphrin basically has a bent shape. So that means if we can somehow build a transition state analog that has the protoporphine with the bent shape, that means that type of molecule will be much more likely to bind into the active side of that particular enzyme, the ferrokeletate.