Through the targeting of matrix metalloproteinase (MMP) inhibitors, such as RECK and TIMP3, as well as tumor suppressors including ANP32A and SPRY2, miR‐21 can increase the expression and activity of various MMPs, facilitate Ras/Raf binding, and induce ERK phosphorylation, thereby enhancing the invasive potential of GBM cells 40, 69, 70. The gene discussed is TIMP3; the disease is glioblastoma.