A downside to apoptosis in cancer therapy?

A recent study challenges the view that radiation-induced apoptosis is beneficial in tumor therapy by showing that caspase 3–mediated apoptosis in response to ionizing radiation activates a growth signaling cascade in tumor cells, thereby stimulating tumor repopulation (pages 860–866). These results may have important implications for the clinical use of radiotherapy or chemotherapy to induce apoptosis in tumors.