Since p38 is a preferred substrate of Mkp-1 [31] and plays a critical role in the regulation of the inflammatory response [25,30,32,33], we assessed p38 activity in the livers of Mkp-1+/+ and Mkp-1−/− mice both before and after E. coli infection (Figure 1A). This evidence concerns the gene DUSP1 and escherichia coli infection.