Proteases do not operate alone, but in linear pathways and amplification cascades (with a one-way flow of information) or in regulatory circuits (with information feedback). By interconnecting between different protease classes, families and pathways, an interconnecting web that we term the ‘protease web’ is formed. The protease web is not in equilibrium but in constant flux, with the connections forming information conducts. The complexity is increased because of the presence of interacting proteins, receptors, substrates, cleavage products and inhibitors. Although proteases are represented as individual squares, these can also represent subnets of several proteases that form a system module, in which a small set of proteases operate together to generate activity and information.
