? Amongst the four """"""""barrier-type"""""""" facilities on the campus of the University of California, San Diego (UCSD), the Liechtag Biomedical Research vivarium includes18 rooms capable of supporting 108 racks and over 17,000 boxes of research mice. Funds are requested to purchase 24 high density mouse caging systems to expand the capacity of available housing space on the UCSD campus. At UCSD, diseaserelated genomic and translational research is a foremost priority. The proposed housing expansion will enable established and newly recruited faculty to conduct seminal studies in cancer biology, hematology, endocrinology, glycobiology, and toxicology. Discoveries in these areas will advance the prevention and safe treatment of important human diseases such cancer, Alzehiemer's and diabetes. In recent years it has become increasingly apparent that immunodeficient mouse strains and mice that are deficient in targeted genes require a stricter level of maintenance that precludes unwanted pathogen exposure. Such """"""""barrier-type"""""""" facilities are critical to maintain the health of the animals and also to prevent spurious experimental results from occult infection and cytokine/chemokine release. ? ? Top Goals for the Animal Care and Use Program at UCSD are to maximize successful research, optimize animal well being, and ensure human health. We are currently focusing on """"""""barrier-type"""""""" vivaria where we are upgrading housing systems for mice involved in PHS funded research. These upgraded housing systems will aid our efforts to maintain critically important animals healthy and free of unwanted mouse microbial agents and pathogens. ? ? Our specific aims are 1) to expand the capacity of """"""""barrier-type"""""""" small animal research facilities, 2) to improve the health of mice by minimizing exposure to pathogens; and 3) to facilitate standardization of experimental results. To address these aims we wish to purchase with this grant 24 of the 108 high density individually ventilated mouse housing systems that are needed to support critical research animals sensitive to relatively minor changes in associated microflora. The University will provide the remaining 44 racks as funds become available. ? ? ?