Macrophages are cells belongs to innate immune system, which response to pathogen by the production of inflammatory proteins those that are effective in both combating pathogen and wound healing. Using small molecule inhibitors it has been shown that many of the inflammatory response genes were under control of BET proteins. We used LysM-Cre to conditionally delete floxed BRD4 in resident peritoneal macrophages and monitored the effect on inflammatory gene expression Overall design: Peritoneal macrophages were treated with either Interferon gamma and IL-4 alone or with LPS and pre treatment of interferon gamma ex-vivo. In some experiment, animals were treated with IL-4 in vivo. RNA was extracted and biotin labeled cDNA was hybridized on Affym3trix microarray. Untreated samples were used as control. To compare differential gene expression samples were prepared from wild type and BRD4 deleted macrophages. Biological duplicates were used for each treatment condition