Apoptosis is the process of programmed cell death. It is a normal and necessary phenomenon for many biological developmental processes, allowing cells to differentiate from each other and to form proper connections. It is also a critical phenomenon in aging and in healthy cell turnover; the healthy adult human body sheds tens of billions of cells each day in order to maintain homeostasis. Excessive or faulty apoptosis is associated with many human disorders such as neurodegenerative and auto-immune diseases and the proliferation of cancers. The machinery and signaling pathways that control cell life and death are key areas in human therapeutic research, the manipulation of which offer great potential to alter the course of many human diseases.