Now, if we examine the structure of alpha one antitrypsin, we're going to find a very important residue, namely methionine 358. And it's the methionine 358, this side chain of methionine 358, that is responsible for actually interacting with the active side of elastics. Now, if these oxidizing agents, as a result of smoking, basically interact with this side chain group, they essentially will oxidize it to form the following product. And this sulfonated product isn't able to actually interact with the active side of the elastase very well. And so we see what smoking does is as a result of the presence of these oxidizing agents, it changes or mutates the structure of the alpha one antitrypsone. So that isn't able to bind to the active side of elastase very well.