And we have other examples of proteases that we're not going to focus on in this lecture. So the question is, what exactly is the mechanism of these other proteases? And how does the mechanism differ or how does it compare to the mechanism inside seren proteases? So let's begin by briefly discussing cysteine proteases. So in cysteine proteases, we also have amino acids in the active side that work together to basically catalyze the cleavage of peptide bonds. But unlike encryption, proteases insisteine proteases, it's the cysteine residue found on the active side that acts as that nucleophilic agent that will cleave that peptide bond.