For instance, MMP-9 has been found to regulate the activity of several signaling pathways essential for GBM growth and survival, including the PI3K/AKT/mTOR, Wnt/β-catenin and Notch pathways, and its knockdown or inhibition has been shown to suppress these pathways, resulting in reduced GBM cell viability and tumor growth, both in vitro and in vivo27. Here, MMP9 is linked to glioblastoma.