To clarify whether the up-regulation of PTEN by TQ and cisplatin led to the apoptosis of gastric cancer cells via mitochondrial pathway, we detected the levels of Bcl-2, Bax, procaspase-9, procaspase-3, Cyt C, AIF, cleaved caspase-9, cleaved caspase-3 using western boltting. This evidence concerns the gene CASP9 and gastric cancer.