Other studies have shown that the TRAIL signaling pathway can activate both the DR pathway and mitochondrial apoptosis pathway (through Bid cleavage) in some cancer cells; however, the enhanced expression of Bcl2 inhibits Bid and subsequently inhibits caspase-9 activation.20 Our previous study shows that Bcl2 expression is higher in both BGC823/DDP and SGC7901/DDP GC cells than in their parent GC cells, that is, BGC823 and SGC7901.41 Compared with that in the cisplatin-sensitive GC cells, Bid expression was higher in the cisplatin-resistant variants (data not shown). Here, CASP9 is linked to cancer.