CXCR4 and breast cancer: C-X-C motif chemokine 12 secreted by CAFs enhances tumor growth by interacting with C-X-C chemokine receptor type 4 (CXCR4), thus inducing downstream signaling cascades, as well as cancer cell proliferation and motility in models of breast cancer [86], endometrial cancer [87], adenocarcinoma of the esophagogastric junction [88] and melanoma [89].