Given that SNORD3A enhanced chemosensitivity to 5-FU depending on UMPS and that SNORD3A acts as miR-185-5p sponge to promote UMPS expression in breast cancer cells, we examined the involvement of miR-185-5p in SNORD3A-mediated chemosensitization to 5-FU. The gene discussed is UMPS; the disease is breast cancer.