Microarray transcription profiling of these B cells in the spleen of BALB/c mice with orthotopic 4T1.2 breast cancer (a model for human triple-negative breast cancer16) surprisingly revealed significant upregulation of macrophage-associated genes, such as CD68, Csf1r (encodes CSF1R), Cebpb (CCAAT Enhancer binding protein beta), Cebpg (CCAAT Enhancer binding protein gamma), Ccl2 (CCL2), and Csf1 (M-CSF) (Fig. 1a). Here, CEBPB is linked to breast cancer.