And what that means is we can build and we can use these suicide inhibitors to basically bind to specific active sites of specific enzymes. Now suicide inhibitors are also known as mechanism based inhibitors. And that's because these suicide inhibitors, they can actually bind onto the active site of that enzyme and begin the normal catalyzation process as if this was a normal substrate molecule. However, down the line, somewhere down that pathway of that reaction, what will happen is that suicide inhibitor will produce a reactive intermediate that will modify the active side in some covalent way. And once that modification takes place, that inhibits that enzyme irreversibly. And so two examples that we commonly use in medicine of suicide inhibitors is penicillin and aspirin.