PARP1 and cancer: These HSP70 knockdown-induced alterations in the protein profile’s expression toward the non-stem cancer cell phenotype were accompanied by a shift towards the upregulation of known effectors of apoptosis, such as cytochrome-c, caspase 3, caspase 7, caspase 9, Apaf1, and others, and downregulation of pro-survival and anti-apoptotic proteins, including poly (ADP-ribose) polymerase 1 (PARP1), Bcl-2, Bcl-xL, survivin, XIAP, and others [118].