Apoptosis is the process of programmed cell death. Upon induction of apoptotic processes, cell undergo characteristic morphological changes (blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, chromosomal DNA fragmentation) and finally die.

Apoptosis has to be clearly separated from necrotic processes, which occur due to cellular injury thus being a kind of traumatic cell death. Apoptosis on the other side is a process which is necessary during the life cycle of organisms.

In a human adult, 50 – 70 billion cells die per day due to apoptosis.

Defective apoptotic processes have been linked to a number of diseases such as cancer (insufficient apoptosis) and atrophy (excessive apoptosis).