We and others have previously shown that miR-31, a BC metastasis suppressor gene, is a major contributor to BC progression and metastasis by regulating a cohort of a pro-metastatic target genes, including WAVE3 [24], RhoA, Radexin [36] and several integrin subunits [47] that regulate key steps in the invasion-metastasis cascade. This evidence concerns the gene RHOA and breast cancer.