This application requests support for the acquisition of a confocal microscopy system. The system requested includes an Olympus BX-61TRF microscope, FV500 3-channel scan unit, argon, green and red lasers, and accompanying computer software. The user group will be comprised of three major users: Dr. Denis Clohisy, Dr. Patrick Mantyh and Dr. Bruce Blazar. These investigators have current NIH support totalling approximately $2.5 million per year in direct costs. The locus of their current funded research is broad, encompassing development of murine models for study and treatment of graft vs. host disease, stem cell transplantation and in utero gene therapy (Blazar); development of munne models for the study and treatment of bone cancer (Clohisy); neurochemical mechanisms of peripheral nociception in inflammation and persistent pain states (Mantyh); and development of munne models for study and treatment of bone cancer pain (ClohisylMantyh). The NIH-funded research projects of these three users will result in full capacity utilization of a confocal microscope and successful, rapid completion of current projects requires seamless access to this technology.