There are reports shown that fibroblasts involve in the cross-talk of cancer cells and fibroblasts by secreting CCL2 [30–32], CCL5 [33], CXCL1 [34], CXCL6 [35], CXCL12 [36], IL6 [37], CXCL16 [38] and others [23–31]. Here, CCL2 is linked to cancer.