By upregulating miR-142-3p, the metastatic potential of breast cancer cells is reduced due to the inhibition of other important molecules for metastasizing, such as C-X-C chemokine receptor type 4 (CXCR4), matrix metalloproteinase-9 (MMP9), or vascular endothelial growth factor receptor (VEGFR), and the expression of protective miRNAs, such as miR-330, miR-145, and miR-34a, is initiated [96]. Here, MMP9 is linked to breast cancer.