HTRA2 and ischemia reperfusion injury: Application of the HtrA2 inhibitor can significantly reduce both caspase 3 and caspase 9 activities, cell apoptosis, and infarction size in both mouse and rat hearts following ischemia/reperfusion injury (Liu H.R. et al., 2005; Bhuiyan and Fukunaga, 2007), indicating that HtrA2 translocated from mitochondria to the cytosol may promote cardiac cell apoptosis in a caspase-dependent pathway.