CASP9 and acute promyelocytic leukemia: Seo et al. reported that treatment with eupatilin in human promyelocytic leukemia HL-60 cells resulted in the release of cytochrome c from mitochondria into the cytoplasm, followed by the sequential activation of caspase-9, -3, and -7 and PARP cleavage, leading to the progression of apoptosis [46].