We first analyzed the levels of expression of miR-379-3p and miR-23c in cell lines belonging to different breast cancer subtypes, such as luminal (MCF-7 and T47D), HER2 positive (SKBr3), basal (MDA-MB-468) and claudin-low (MDA-MB-231) cell lines. The gene discussed is ERBB2; the disease is breast cancer.