PTGER4 and myocardial infarction: In the current study, we discovered novel mechanism that provides the basis of cardiac repair after 12/15LOX deletion: 1) increased EP4 expression in reparative MΦ during acute phase; 2) upregulation of miR23a in infarcted heart facilitating cardiac repair; 3) increase in post-MI survival and LV function during CHF; and 4) decreased in cardiorenal inflammation during CHF.