Now, what about the final mechanism? So, notice, in the intrinsic pathway and the extrinsic pathway, we both used a category of protease proteins known as caspase. The major difference between the final mechanism and these two mechanisms is that this does not actually include a caspase protein. It includes its own molecule known as apatosis inducing factor or AIF. So the final mechanism of apatosis involves using apatosis inducing factor AIF to actually initiate the process of apatosis. This process does not use cast spaces.