This term was created to reflect the fundamental role of the mitochondrial compartment in apoptosis. Most processes under this node occur during the signaling phase of apoptosis, but e.g. GO:0043653 'mitochondrial fragmentation involved in apoptotic process' cannot be confidently placed under the signaling phase. For this reason, the parent term GO:0008637 'apoptotic mitochondrial changes' is not linked to the signaling or execution phase specifically, but its descendants are when current knowledge allows for it.