occurs in has result has context release of cytochrome c from mitochondria mitochondrion ER stress dependent process endoplasmic reticulum stress [toxic course] release of cytochrome c from mitochondria [ER stress] Permeabilization of the outer mitochondrial membrane by pro-apoptotic BCL2 family proteins, such as BAK and BAX, allows cytochrome c eflux from the mitochondrial intermembrane space into the cytosol (Arnoult et al. 2003). Reactome:R-HSA-114284 The process that results in the movement of cytochrome c from the mitochondrial intermembrane space into the cytosol, which is part of the apoptotic signaling pathway and leads to caspase activation. This entity is a specific course-dependent process. This process can constitute the course of ER stress. apoptosome assembly [ER stress]