Different tumour cells reveal variable sensitivities to JS-K, which might be attributed to resistances to NO-induced cell death mechanisms such as the expression of the detoxification enzymes GSTs.33 Even if there are many indications in this study that necrosis plays the major role in cell death by JS-K, apoptosis is also induced in a small population of cells what might be due to the effect of extrinsic signals by this population itself. This evidence concerns the gene HPGDS and neoplasm.