Lei (Lei, 2013) reported that turmeric volatile oil inhibited the proliferation of liver cancer cells (Bel-7402, HepG2, and SMMC-7721) mainly by activating the mitochondrial apoptotic pathway, down-regulating the expression of Bcl-2 in the Bel-7402 liver cancer cells, reducing the levels of cytochrome C in the mitochondria, and by up-regulating Bax and activating the expression of caspase-9- and caspase-3-induced apoptosis in liver cancer cells. This evidence concerns the gene CASP9 and liver cancer.