Oma1 deletion restores apoptotic resistance of Phb2-deficient cells but does not protect against TNF-induced necroptosis. (A and B) Oma1 deletion protects Phb2-deficient MEFs against H₂O₂-induced apoptosis. siRNA-treated wild-type (WT) and Oma1^−/− cells were exposed to 1 mM H₂O₂ for 7 h. (A) Analysis of the accumulation of apoptotic marker proteins by immunoblotting. β-Actin was used as a loading control. (B) Flow cytometry analysis of viable cells (7-AAD–negative, Annexin V–negative; n = 3). **, P < 0.01. Error bars indicate SD. (C) Oma1 deletion does not confer necroptotic resistance. Cell viability of Oma1-deficient MEFs was analyzed upon induction of necroptosis. –, DMSO; C, cycloheximide; T, TNF; Z, Z-VAD-FMK; N, necrostatin-1. *, P < 0.05. Error bars indicate SD.