Untreated knockout serum contained lower levels of known proinflammatory and chemotactic cytokines, including eotaxin, IFN-γ and MCP-1α [44-46], as well as other contextually-dependent proinflammatory signals, such as IL-4 and GM-CSF [45], that could have possibly rendered PPARγ-MG KOs less susceptible to breast cancer compared to PPARγ-WTs when challenged with DMBA. This evidence concerns the gene CSF2 and breast carcinoma.