Although the tumor suppressor role of miR-491-5p in breast cancer has been depicted in several studies such as preventing proliferation, apoptosis, migration and invasion by targeting ZNF-703 [10,12] and inhibiting cell growth by targeting JMJD2B [9], the precise role of miR-491-5p in TNBC has never been elucidated. The gene discussed is KDM4B; the disease is breast carcinoma.