What is apoptosis? Apoptosis is the most common form of programmed cell death (PCD) that occurs in multicellular organisms. It can be triggered via various physical, chemical, and biological factors, and by mild cellular injury. Apoptosis is a normal physiological process, cancer can be formed in the body without apoptosis.
Apoptosis is a common physiological process (As the figure 1 shows). It is characterized by these features:
Figure 1. The diagram of Apoptosis
As mentioned in the article entitled "An Overview of Cell Death: Necrosis and Apoptosis", two core pathways are involved in the process of apoptosis, including extrinsic pathway and intrinsic pathway. Different gene families such as Bcl2 family, caspases, death receptors ligands, inhibitor of apoptosis proteins, mitochondrial control of apoptosis are involved in the process of apoptosis.
CUSABIO lists partial popular targets related apoptosis, click to see all the related molecules/targets and research reagents of them.
Bcl2 Family is the best characterized protein family involved in the regulation of apoptotic cell death, including anti-apoptotic and pro-apoptotic members. The anti-apoptotic members of this family, such as Bcl-2 and Bcl-XL, prevent apoptosis either by sequestering pro-forms of death-driving cysteine proteases called caspases or by preventing the release of mitochondrial apoptogenic factors such as cytochrome c and AIF into the cytoplasm. In contrast, pro-apoptotic members of this family, such as Bax and Bak, trigger the release of caspases from death antagonists via heterodimerization and also by inducing the release of mitochondrial apoptogenic factors into the cytoplasm via acting on mitochondrial permeability transition pore, thereby leading to caspase activation .
Caspases are a family of genes important for maintaining homeostasis through regulating cell death and inflammation. Caspases involved in apoptosis have been subclassified by their mechanism of action and are either initiator caspases or executioner caspases. Initiator caspases activate executioner caspases that subsequently coordinate their activities to demolish key structural proteins and activate other enzymes .
Death receptors ligands are series specific death ligands of death receptor (DR). When the death receptor combines with specific death ligand, it receives extracellular death signal, and activates the mechanism of apoptosis in cells, inducing apoptosis. More information of death receptors>>
Inhibitor of apoptosis proteins (IAPs) are best known for their ability to regulate cell survival and death processes. IAPs were first identified as a class of baculoviral proteins that prevented apoptosis of insect cells during baculoviral infection  .
Mitochondrial control of apoptosis: Mitochondria play key roles in activating apoptosis in mammalian cells. Bcl-2 family members regulate the release of proteins from the space between the mitochondrial inner and outer membrane that, once in the cytosol, activate caspase proteases that dismantle cells and signal efficient phagocytosis of cell corpses. More information of mitochondrial control of apoptosis>>
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 David R. McIlwain, Thorsten Berger1 and Tak W. Mak. Caspase Functions in Cell Death and Disease [J]. doi: 10.1101/cshperspect.a00865
 Hrdinka, M., & Yabal, M. Inhibitor of apoptosis proteins in human health and disease [J]. Genes & Immunity. 2019.
 Crook NE, Clem RJ, Miller LK. An apoptosis-inhibiting baculovirus gene with a zinc finger-like motif [J]. J Virol. 1993;67:7.