The survival analysis from the Kaplan-Meier Plotter demonstrated that a higher mRNA level of CXCL9 was related to better RFS (Relapse free survival, Figure 4A, ER-, HR=0.62, P<0.01; Figure 4B, ER+, HR=0.62, P=0.61), DMFS (Figure 4C, ER-, HR=0.57, P<0.05; Figure 4D, ER+, HR=1.21, P=0.26) and OS (Figure 4E, ER-, HR=0.54, P<0.01; Figure 4F, ER+, HR=1.11, P=0.56) in BC patients in the ER-negative subgroup, whereas no significant difference was found in BC patients in the ER-positive subgroup. This evidence concerns the gene CXCL9 and breast cancer.