In senescent mice, the protective effects of iPOST on myocardial ischemia are attenuated, with a proposed explanation being a decrease in ERK phosphorylation and an increase in MKP-1 (mitogen-activated protein kinase phosphatase-1; see Box 1) expression in the aged heart (Przyklenk et al., 2008a). The gene discussed is DUSP1; the disease is myocardial ischemia.