Akt and mTOR contribute to triggering apoptosis through some molcular pathways leading to permeabilization of mitochondrial membrane and release to pro-apoptotic factors, notably cytochrome c to cytoplsma; it unlikely that they activate death receptor apoptotic pathway, as they are unable to ligate and oligomering the receptors. The expression of caspase-3, or more precisely pro-caspase-3 does not induce apoptosis. It contributes to induction of apoptosis when it is cleaved or processed when its active domain is released after removing of pro-domain(s). Then released fragment activates the downstream effects of apoptosis by lysis of the cell death related substrates.