This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Inflammation is central to our fighting against pathogens, but if not controlled in a proper manner, can contributes to disease including cancers. Population based studies showed that long-term use of non-steroidal anti-inflammatory drugs reduces the risk of several cancers. Moreover, most solid tumors contain many inflammatory cells that play an important role in tumor progression. However, importance of inflammatory cells in human B lymphoma progression has not been recognized until recently. Microarray gene expression profiling studies have identified gene signatures predictive of tumor behavior and patient outcome in B lymphomas. Surprisingly, these data uncovered a strong role for immune response in the pathogenesis and progression of B lymphoma by identifying 2 prognostic signatures based upon nonmalignant tumor infiltrating cells rather than characteristics of the tumor cells. These two signatures, one reflecting expression from macrophage and the other reflecting expression from T cells, have been shown to be associated with patient survival. Hence, understanding the roles of host immune cells in B lymphoma progression deserves further exploration and would potentially lead to a new therapy targeting microenvironment in B cell lymphoma. In this study, we propose to determine the role of lymphoma associated macrophages (LAM) in B lymphoma progression.