C57BL/6 Wild-type (WT) and CARD9-/- mice were subjected to 45 min occlusion of left anterior descending (LAD) coronary artery followed by 24 h of reperfusion. A: Representative heart sections stained with Evans blue and TTC to determine the total area of left ventricle (LV), area at risk (AAR, free of blue color) and infarct area (pale color); B: Analyses of the ratio of AAR/LV and infarct size (the ratio of infarct area/AAR) in the hearts of WT and CARD9-/- mice. There was no significant difference in AAR/LV between the two groups, however the infarct size was significantly smaller in the CARD9-/-+I/R group than that in the WT+I/R group. Mean ± SEM, n = 5/group, **p < 0.01, CARD9-/- vs. WT.