MMP9 and cancer: Previous reports have indicated that miR-194-3p functions as a tumor suppressor and prognostic marker in multiple types of cancers, and directly targets mRNA of multiple oncogenes, including PRC1, RUNX2, DPAK1, MECP2 and MMP9 (Abuduaini et al., 2018; Yi et al., 2019; Zhou et al., 2020).