Given a vast body of literature linking c-MYC expression to positive regulation of cell proliferation [42–44] and our results that ADA3 regulates c-MYC levels (Additional file 1: Figure S2), [3, 4], we assessed the impact of overexpressing ADA3 in ER+ breast cancer cell lines and then analyzed the relationship of nuclear ADA3 and c-MYC expression in ER+ breast cancer specimens. This evidence concerns the gene MYC and breast cancer.