Apoptosis or programmed cell death

Apoptosis or programmed cell death is a genetically controlled response for cells to commit suicide. Regulation of cell death is essential for normal development and is an important defense against viral infection and the emergence of cancer. Too much cell death can lead to impaired development and degenerative diseases, whereas too little cell death can lead to cancer and persistent and sustained viral infection. In this review are briefly described: a) the symptoms of apoptosis (viability loss accompanied by cytoplasmic boiling, chromatin condensation, and DNA fragmentation; b) the genes which control the process of apoptosis and which are conserved in nematodes through mammals and viruses; b) the signals and the biochemical pathways which seem to be involved in the induction of apoptosis and d) the human diseases which pathogenesis appear to be linked to alterations in cell survival.