Our data showed that miR-148b, miR-21 and miR-155 were significantly overexpressed in tumor tissues versus normal tissues. While miR-221 expression was not significantly different, miR-10b was also found to have significantly decreased expression in tumor compared to normal tissues. The upregulation of miR-21 and miR-155 in tumor versus normal tissues was consistent with the literature and their oncogenic role. miR-21 has been reported as an oncomir that contributes to motility invasion and metastasis by targeting tumor suppressors such as phosphatase and tensin Celastrol homolog, tropomyosin 1, programmed cell death 4 and mammary serine protease inhibitor. miR-155 has been also shown to be an oncomir acting as apoptosis suppressor and inducer of cell proliferation and chemoresistance through targeting Mogroside-V Caspase3, suppressor of cytokine signaling 1 and Forkhead transcription factor tumor suppressors. On the contrary, the upregulation of miR-148b was not in accordance with its reported function as a tumor suppressor that was downregulated in breast tumors. However, our results are in agreement with the increased expression of miR-148b obtained in ovarian carcinoma. Interestingly, miR-148b was also shown to be upregulated in the serum of young-aged breast cancer patients. Downregulation of miR- 10b, an oncomir with metastatic potential, was obtained in metastasis free patients and that is the case with patients in this study who mostly have no metastasis. As for miR-221, no significant difference in its expression was obtained in Lebanese breast cancer patient population which contrasts previous reports that demonstrated its increase in breast cancer due to its oncogenic role by regulating proliferation, angiogenesis and multiple tumor suppressors. Hence, differentially expressed miRNA between normal and tumor breast tissues could be variable between Lebanese and Western populations. Remarkably, it was previously found that there is little overlap between the differentially expressed miRNAs identified from Caucasian American breast cancer patients and those from African American groups, suggesting a potential ethnic difference in miRNAs.