CASP3 and myocardial infarction: Cardiac cell death and collagen synthesis contribute to post-MI cardiac dysfunction.36,37 We have previously shown that the apoptotic cells in the myocardium in post-MI mice are mostly cardiomyocytes.18 Immunofluorescent double staining and confocal imaging showed that, at both 1 and 7 days post-MI, troponin and cleaved caspase-3 double positive apoptotic cardiomyocyte contents increased in Rorafl/flIl7rCre/+ mice in both the infarct and border regions (Figure 7A and B).