One possible mechanism for this refractory disease lies in the coordinated interplay between tumor cells and cancer-associated fibroblasts (CAFs), including that through the C-X-C chemokine receptor type 4/C-X-C motif chemokine 12 (CXCR4/CXCL12) signaling [2, 3]. This evidence concerns the gene CXCR4 and cancer.