And once bound, it acts in a process known as oxygenization, meaning it calls upon these phagocytic cells, for example, macrophages or neutrophils. And then these phagocytic cells come nearby and basically phagocytes, they engulfed these pathogenic agents. Now, the other function of C three B is to basically go on and bind onto an allosteric site found on a C Five protein. And by binding to the C Five protein, it basically creates a conformational change and it prepares it for cleavage by the C four B C two B complex. Remember, this complex doesn't only activate C three, it also activates C Five. So we have this very complex mechanism where many different proteins activate other proteins.