Among them, matrix metallopeptidase 14 (MMP14), which is located on the surfaces of BC cells, was shown to be active in collective migration [134], and the up-regulation of MMP14 and the down-regulation of the targeting of miR-181a-5p were more pronounced in the invasive front of breast tumors than in adjacent normal tissue [135]. The gene discussed is MMP14; the disease is breast cancer.