Given that endothelial cells, neutrophils, and monocytes are all sources of MMP-9 [27], [28] and MMP-9 levels were all increased after the ischemia/reperfusion induced by hemorrhagic shock, MMP-9 may be activated by the ischemia associated with hemorrhagic shock rather than only by specific events in the intestine. This evidence concerns the gene MMP9 and ischemia.