MiR-26a/26b expression was significantly decreased in breast cancer tissues compared with normal tissues, and it was found associated with proliferation and motility in MDA-MB-231 and MCF-7 cell lines, indicating the diagnostic potential of miR-26a/26b in breast cancer.20, 21 Moreover, we detected that decreased levels of miR-26a/26b correlated with the upregulation of ST8SIA4 expression in the patients, as well as in cell lines. This evidence concerns the gene ST8SIA4 and breast cancer.