PPIF and ischemia: The improved protection against I/R injury with CypD ablation was associated with significantly increased mtHK activity (0.061 ± 0.009 vs 0.12 ± 0.01; p = 0.02) and reduced cytosolic HKII amount (1 ± 0.07 vs 0.63 ± 0.07; p = 0.004) at end-ischemia (Fig. 7a,d and f, respectively).