Transfection of a recombinant plasmid containing pcDNA-AEG-1/MTDH-microRNA (miR)-4 significantly suppresses AEG-1/MTDH at the mRNA and protein levels by >69% in MDA-MB-231 breast cancer cells, and significantly inhibits proliferation, motility and migration compared with controls (90). This evidence concerns the gene MTDH and breast carcinoma.