Expression of miR-218-5p was low in non-malignant, ER- epithelial MCF-10A cells and in early-stage, non-metastatic ER+ MCF-7 breast cancer cells and significantly increased in two sublines of ER- metastatic MDA-MB-231 breast cancer cells that grow aggressively in bone (Figure 1C). The gene discussed is ESR1; the disease is breast carcinoma.