CASP3 and cancer: The most prominent induction of caspase-3/7 activity and cleaved PARP expression by the dual targeting HSP90 and HSP70 using 17-AAG and PFT-μ with a chemotherapeutic agent was evident in this study; these results suggested that this trimodal anticancer treatment could induce strong activation of the caspase-dependent apoptosis pathway and exhibit more cytotoxicity to cancer cells.