CXCL12 and breast cancer: CXCL12: The ability of 17β-estradiol to robustly increase expression of the chemokine CXCL12 in breast cancer cells was reported by the Korach lab and others [198,199,200], and was confirmed in multiple GEO datasets [201,202,203,204,205,206,207,208] (Supplementary Table S1).