MMP9 and hemorrhagic stroke: Furthermore, β-pix, which genetically interacts withccm1 and pak2a (Buchner et al., 2007; Gore et al., 2008; Liu et al., 2007), is downregulated, while thehemorrhage-induced inflammatory mediator mmp9 is upregulated,suggesting that this mutant recapitulates many aspects of hemorrhagic stroke inhumans.