These include the identification of miRNAs essential for HER2-positive breast cancer cell growth7, miRNAs that regulate estrogen receptor signaling8, miRNAs that increase the proliferation of breast cancer cell lines9, miRNAs acting as metastasis suppressors in breast cancer10, miRNAs positively regulating cell migration and invasion11, and previously we linked a high expression level of miR-29c to disease specific survival12. The gene discussed is ESR1; the disease is breast cancer.