And we know that the structure of this looks nothing like the structure of either of these two substrates. And so what that means is for CTP to actually inhibit the activity of atcase it must bind onto some other side other than the active side. And those sites, as we said previously, are known as allosteric sites, regulatory sites. So we see that in this biological synthesis of CTP, it's the end product. It's the CTP itself that goes back to the beginning, to the first step in the reaction and inhibits the activity of this aspartate transcarbolase. And we know from basic biology that this type of pathway is known as the negative feedback loop or negative feedback inhibition.