Huang L et al. [30] reported that miR-224 inhibits RKIP expression in highly invasive breast cancer cell lines through the binding of its 3′-untranslated region (3′-UTR) that, in turn, leads to the upregulation of CXCR4, MMP1, and OPN, which are involved in breast tumour metastasis to the bone. This evidence concerns the gene PEBP1 and breast cancer.