And that causes the death of that cell. And once the cell actually dies off, some type of phagocytic cell, for example, a macrophage, swims by and engulfs that cell. And so this is one mechanism by which this process of apatosis takes place and involves this special type of active protein known as Cat Space Nine. Now, this entire process takes place inside that cell. It initiates and takes place inside the cell. What about the extrinsic pathway?