Apoptosis can be triggered through two main pathways: the intrinsic (mitochondrial) pathway and the extrinsic (death receptor) pathway. The intrinsic pathway is activated by internal signals, such as DNA damage or oxidative stress, leading to the release of cytochrome c from mitochondria. The extrinsic pathway is initiated by the binding of external ligands to death receptors on the cell surface, such as Fas or TNF receptors.
