TIMP3 and glioblastoma: In addition to its role in proliferation and cell survival, miR-21 has been implicated in regulating GBM cell migration and invasion potential by suppressing matrix remodeling proteins that normally regulate the levels of matrix metalloproteinases (MMPs) such as TIMP3 (tissue inhibitor of metalloproteinases 3) and RECK (reversion inducing cysteine rich protein with Kazal motifs), ANP32A, and SPRY2 [63,113].