By comparative analysis of the pERK levels in WT and Dusp6-deficient PMNs, we found that basal pERK increased in resting PMNs from Dusp6-deficient hearts without MI surgery, but the level of pERK in PMNs in Dusp6-deficient heart at 6 h, 24 h, and 72 h after MI did not increase and rather slightly decreased at 24 h after MI compared with those in WT hearts (Fig. 7b, c). This evidence concerns the gene DUSP6 and myocardial infarction.