First paragraph (this article has no abstract)

The development of the breast is exquisitely sensitive to interactions between the epithelium and stroma. Experimental evidence indicates that a reduction in signalling between any of the stromal cell types (fibroblasts, macrophages, endothelial cells and adipocytes) results in reduced or absent breast development [1], although all interactions appear to be orchestrated by the epithelial cell oestrogen receptor alpha [2]. The epithelial-stromal interactions that occur in tumours are less well characterised but there is no doubt there is expansion of the stroma as well as of the epithelium during tumour development [3,4]. Recent data indicate that the prognosis after breast cancer diagnosis relates to stromal type, and experimental and clinical studies directed at modifying the stroma (for example, angiogenesis inhibitors) suggest that the stroma is a target for therapy that is worthy of further exploration