Since DUSP6 is a well-known phosphatase specifically against ERK1/2 phosphorylation11, we first assessed the pERK level in isolated PMNs by Western blot, and found that pERK in PMNs increased from 6 to 24 h, and then decreased to the basal level at 72 h after MI compared with the non-surgery group (Fig. 7a). Here, MAPK3 is linked to myocardial infarction.