Knockdown FAK by siRNA significantly decreased CXCL7-promoted migration (Fig. 3D) while treatment with the MMP-13 inhibitor significantly suppressed CXCL7-induced cell invasion in MDA-MB-231 cells (Fig. 3E), suggesting that CXCL7 promoted breast cancer migration/invasion through FAK- and MMP13-mediated signaling pathways. Here, PPBP is linked to breast cancer.