BIRC5 and cancer: Cell-based mechanistic studies indicated that PZ-6-QN enters mitochondria to inhibit the survivin-Smac interaction and promotes the release of Smac and cytochrome c from mitochondria into cytosol; and importantly, PZ-6-QN exhibits good anticancer activity against various cancer cells including HeLa, A549, HCT116 and MCF-7 [23].