Indeed, low levels of the negative Notch regulator miR-34a were associated with a worse response of colon cancer patients to 5-FU, and its overexpression overcame ABCG2-mediated resistance of a stem cell-like subpopulation of colon cancer cells to 5-FU through downregulation of DLL1/Notch signaling. The gene discussed is ABCG2; the disease is malignant colon neoplasm.