CASP3 and retinoblastoma: These observations are consistent with recent studies showing that the lysosomal translocation of cathepsin D in human retinoblastoma Y79 cells promotes mitochondrial membrane permeability thus resulting in apoptosis.40 Furthermore, cathepsin B is abnormally active and results in similar events in pancreatic cancer cells.41 We show that curcumin significantly stimulates cathepsin activity, which may affect the cleavage of Bid and the subsequent delocalization of Bax to the mitochondrial membrane followed by caspase-3 activation.