Conversely, another recent mouse study reported that whilst while MMP9 inhibition improved specific neurobehavioral deficits associated with AD (such as anxiety and social recognition memory), modulation of MMP9 did not alter spatial learning and memory or Aβ tissue levels in AD animals, suggesting that further work is necessary to understand the nature of the relationship between MMP9 activity and neurological dysfunction in mice. This evidence concerns the gene MMP9 and Alzheimer disease.