Fig. 5.

Regulation of apoptosis. Apoptosis can be induced via the death-receptor-dependent pathway (extrinsic pathway) or the mitochondria-dependent pathway (intrinsic pathway). The extrinsic pathway is initiated in the liver by death ligands such as TNF, Fas ligand (FasL, CD95L), and TRAIL (TNF-related apoptosis-inducing ligand), following their binding to their relevant death receptors. In contrast, the intrinsic pathway is triggered by a variety of intracellular stressors such as DNA damage, growth-actor deprivation, and metabolic disturbances from the extracellular matrix and/or surrounding cells.