MMP9 and brain disorder: It was also found that in pathological conditions abnormal MMP-9 release contributes to the development or influences the course of many brain disorders, including epilepsy, autism spectrum disorders, brain strokes, brain tumors, neurodegeneration, brain injuries, schizophrenia, and alcoholism (Reinhard et al., 2015; Vafadari et al., 2016; Pijet et al., 2018; Beroun et al., 2019; Bitanihirwe and Woo, 2020; Go et al., 2020; Yin et al., 2020; Gore et al., 2021).