By using this approach, our group has previously demonstrated that a specific stromal gene expression pattern, the DTF fibroblast signature, could robustly and reproducibly define a subgroup of breast cancer patients with good prognosis [2,8] and that a second stromal pattern, the TGCT/CSF1 macrophage signature, is associated with breast cancers of a higher tumor grade, with decreased expression of ER/PR, and increased mutations of TP53 [1]. Here, CSF1 is linked to breast cancer.