To investigate the potential roles of miR-205, miR-206 and miR-548i-4 on the growth of cell lines with different levels of endogenous Myc expression, we next stably expressed each of the three miRs in MCF-7 and MB231 breast cancer and HepG2 hepatocarcinoma cells (Supplementary Figure 2A). The gene discussed is MYC; the disease is breast cancer.