MMP9 and cancer: Overexpression of Stat3 and IL‐6 could induce the expression of HIF‐1α and VEGF.36, 37 Blockade of pStat3 can reduce the expression of HIF‐α, VEGF, MMP2 and MMP‐9 and inhibit the proliferation and invasion of cancer cells.38 Our results demonstrated that inhibition of Stat3 decreases the metastatic potential of ovarian cancer cells.