In addition, macrophages are a major population of infiltrating cells in the tumour stroma; it is possible that VEGF and TF-expressing macrophages, observed in this study, may have a role in regulating the angiogenic switch and tumour progression in human breast cancer, as previously described in an autochthonous mouse model of breast cancer (Lin et al, 2006). This evidence concerns the gene VEGFA and neoplasm.