IFN-γ exposed breast cancer cells were used as controls in the subsequent experiments, because IFN-γ is a strong inducer of CXCR3 ligand expression, and the anti-tumor effects of CXCL9 and CXCL10 have been shown to be IFN-γ dependent in mouse models [16,30,31]. This evidence concerns the gene CXCL9 and breast cancer.