We also have chimotrypsin and chimotrypsin cleaves at the carboxylan of tyrosine, methionine, phenylalanine, tryptophan, and leucine. So basically, if we have some type of amino acid that contains an aromatic ring, this is our protein enzyme that cleaves it. And finally, another example is thrombin. And this is found in our blood clotting cascade. So what thrombin does is it cleaves at the carboxyl side of arginine. And we have many, many more examples of such biological enzymes in our body as well as in other organisms.