CD9 and breast cancer: Transfection of breast cell lines with miR-518f-5p mimic resulted in a significant decrease in CD9 total protein expression in non-tumorigenic 184A1 (Figure 2G,H; 64.12% decrease, p = 0.0017) and triple negative MDA-MB-231 breast cancer cells (Figure 2G,H; 36.16% decrease, p = 0.0287) compared to NTC cells, as measured by SDS-PAGE and Western blotting.