The results of Hoechst 33342 staining, annexin V/PI staining, JC-1 staining, and western blot revealed that GE induced apoptosis of ovarian cancer cells that caused the cleavage of caspase-3 and PARP, and it demonstrated stronger apoptotic-inducing effects than other xanthones in this study (data not shown). Here, CASP3 is linked to ovarian cancer.