RIPK3 and neoplasm: This notion was bolstered by the observation that apoptosis-resistant but IAP antagonist plus caspase inhibitor (IZ)-sensitive lines exhibited expression of RIPK3 (Figures 1b and c), a critical regulator of necrotic cell death.11 Further supporting this possibility, cell death induced by IZ was not accompanied by the activation of caspases, as occurs during apoptosis (Figure 1d).6 As the concept that tumor cells (in particular serous ovarian tumor cells) might be sensitive to necroptosis had not been previously explored, we characterized this cell death further.