HTRA2 and myocardial ischemia: Furthermore, HtrA2 may be a potential biomarker for the identification of ischemia/reperfusion injury because the levels of Htra2 in blood serum are significantly increased in mice with myocardial ischemia/reperfusion injury and also in human patients with ST-segment elevation myocardial infarction (Hortmann et al., 2019).