CCNB1 and breast carcinoma: Other studies pointed to a tumor-suppressor role of these miRNAs in breast cancer, for instance hsa-miR-99a-5p reduces breast cancer cell viability by targeting mTOR [71], hsa-miR-125b-5p was shown to induce cell cycle arrest and reduce cell growth in breast cancer cells [72], and hsa-miR-379-5p was shown to regulate Cyclin B1 expression [73].