The potential side effects of non-specific MMP-9 inhibition to treat neurodevelopmental disorders have not been thoroughly investigated, though MMP-9 KO mice have shown detrimental side effects as well as benefits in animal models of cancer (Coussens et al., 2000) and kidney disease (Zeisberg et al., 2006) and highlight the need for treatments specific to both the CNS and to key points in the progression of a disorder. The gene discussed is MMP9; the disease is kidney disorder.