FOSL1 and breast neoplasm: A recent study suggested that up-regulation of Fra-1 in tumour-associated macrophages, which is dependent on the interaction between stroma and breast tumour cells, may have a pivotal role in tumour progression.33 The mechanism may be related to activation of signalling pathways releasing soluble factors that, in turn, lead to increased production of angiogenic factors and proteases by tumour cells.