And what that means is it can go on and activate other proteins that are part of the classical pathway by cleaving them at specific amino acid sequences. So to see what we mean, let's take a look at the following diagram. So this is the entire C One complex. When the C one complex binds onto the antibody antigen complex, it basically is activated. And then the C one S portion, these two proteins here basically go on and they cleave the C two and the C four proteins also part of the classical pathway. So we cleave the C two into C two a and C two b.