MiR-494 could suppress the progression of BN in vitro by targeting CXCR4 through the Wnt/β-catenin signaling pathway [100]; and the expression level of miR-30e was lowered in both plasma and breast cancer tissues of BN patients and plasma miR-30e expression was statistically related to the patients age and clinical stage of BN [101]. This evidence concerns the gene CXCR4 and breast cancer.