Fig. 8. Proposed model for the initiation of apoptosis by cell shrinkage. Cell shrinkage may result in the increased concentration of auto-activating enzymes (top panel) or the increase in proximity of cell surface receptors (bottom panel). The activation of such enzymes/receptors may result in the initiation of apoptosis in the absence of other drugs or the acceleration of the pathway in the presence of other apoptosis initiators.