This application for the Laboratory Animal Major Equipment Program (LAMb) requests support to purchase a high-density individually-ventilated mouse caging system for the vivarium at Michael E. DeBakey VA Medical Center (MEDVAMC). This is a facility-wide enhancement that will be available to all researchers housing mice at our facility, including the 7 VA investigators listed in the application. The new caging system will provide improved microenvironment for laboratory animals, will reduce the exposure to allergens for laboratory personnel, will integrate with the facility's recently acquired automated watering system and will enhance utilization of space in the vivarium. These improvements to the vivarium at MEDVAMC will enhance the ability of the facility to retain and recruit successful investigators whose research depends upon a high-quality microenvironment for rodent housing.