miR-520c and miR-373 upregulate MMP-9 expression and enhance human fibrosarcoma cell migration and growth not by direct binding to the MMP-9 promoter, but by directly targeting the 3′-UTR of the mRNAs of mTOR and SIRT1, which are negative regulators of MMP-9 expression [58]. Here, MMP9 is linked to fibrosarcoma.