Recent studies in breast cancer cells have revealed that CXCR7 activation by SDF‐1 increases components regulating cell adhesion and cell–matrix interaction, such as vascular adhesion molecule VCAM‐1 and matrix metalloproteinases MMP‐2 and MMP‐9 (Wani et al., 2014), and SDF‐1 also promoted MMP‐9 expression in OC cells (Yu et al., 2014). This evidence concerns the gene MMP9 and breast cancer.