This star-shaped protein complex is called an apoptosome, and it is constructed in your cells to bring about cell death. It's actually part of the cell's self-destruct system. When a cell becomes stressed or old and ceases to function properly, a series of signals bring about apoptosis, or programmed cell death. This is a good thing, and part of the natural life cycle of a cell. Unfortunately, this process can be blocked in cancer cells, preventing your immune system from killing them off.