Programmed cell death, exactly. It may be that in the body, with 80 trillion to 100 trillion cells, we have up to one million cells per second going through this process of cell destruction, programmed cell death, and recycling without damaging neighbouring cells. It's an amazing phenomenon. Of course there's a lot of interest in apoptosis, because in cancer research now, we find tumour cells are full of an anti-apoptotic protein of several types, and viruses are able to introduce this kind of anti-apoptotic protein. It's key to understanding what's going on in the cells.
Does any of your research indicate that in fact when cells are stressed—you mentioned stress proteins, the cell response to stress—the stress response includes triggers that may in fact induce apoptosis in the cells, which can in fact trigger tumours under the right condition?