DUSP6 and myocardial infarction: In contrast, the Dusp6-deficient hearts had better systolic performance and smaller cardiac dilatation than the WT sibling hearts at 4 weeks after MI, as indicated by better preserved ejection fraction and fractional shortening as well as smaller LV end-diastolic volume and end-systolic volume (Fig. 1a, b and Supplementary Table 3).