MITOCHONDRIA CONTROL cellular life and death. “Thus, with a relatively small number of proteins, mitochondria operate as highly specialized cellular sentinels that continuously monitor the conditions of the cell to finely adapt its metabolic activity, to coordinate adaptive responses to stress, and to decide on its final and inexorable fate. Not bad for an intracellular bug.”
http://circres.ahajournals.org/content/111/9/1198.full