To further confirm that GSPs-induced activation of caspase-3 is involved in the induction of apoptotic cell death of A549 and H1299 human lung cancer cells, we determined whether the GSPs-induced apoptosis of A549 and H1299 cells was affected by the addition of the caspase-3-specific inhibitor (z-DEVD-fmk). This evidence concerns the gene CASP3 and lung cancer.