MMP9 and epilepsy: Next, Wilczynski et al. and Mizoguchi et al. demonstrated the functional involvement of MMP-9 in experimental models of epileptogenesis, employing mice missing the MMP-9 gene that were impaired in developing epilepsy, and rats with additional MMP-9 gene copies, selectively expressed in neurons, which resulted in an enhanced susceptibility to epileptogenesis [19,20].