Supernumerary, old or damaged cells of multicellular organisms are eliminated by apoptosis – programmed cell death. Apoptosis is accompanied by series of characteristic morphological and biochemi- cal events. The cell activates a cascade of cysteine proteases – caspases, that digest target proteins. Nucleases are also activated, which together leads to irreversible cell damage within few hours. Mitochon- dria are the cell compartment that integrates signals from different apoptotic pathways activated by ischemia, heat shock or growth hormones depletion.