JPH2 and myocardial ischemia: Schulz and colleagues showed that MMP-2 is activated and thereby degrades myocardial contractile proteins such as myosin light chain [30], titin [31] and troponins [16], as well as sarcoplasmic/ endoplasmic reticulum Ca2+ ATPase 2a (SERCA2a) [32] and junctophilin-2 [33] (see [34,35]) during myocardial ischemia/reperfusion injury.