In summary, by using integrated bioinformatics analyses of multiple datasets of gene expression profiles in BC in clinical settings, we identified 10 robust hub genes—CXCL10, CXCL9, CXCL11, SPP1, POSTN, MMP9, DPT, COL1A1, ADAMDEC1, and RGS1—that together may serve as a risk factor for BC diagnosis and prognostication. This evidence concerns the gene MMP9 and breast cancer.