Polymorphonuclear neutrophils (PMNs) isolated from intracerebral hemorrhage (ICH) rats stimulated with IL-27 revealed reduced inducible nitric oxide synthase (iNOS), matrix metallopeptidase-9 (MMP-9), and NADPH oxidase 2 (NOX2); increased hemoglobin-neutralizing Hp and iron-sequestering LTF, IL-27rα, and gp130; and increased the phosphorylation expression of STAT3 (41). Here, MMP9 is linked to intracerebral hemorrhage.