Abstract: Cytometry Facility (CF) The Hillman Cancer Center (HCC) Cytometry Facility (CF) has been in continuous operation since 1991 and has consistently provided HCC members with state-of-the-art cytometry instrumentation and expertise. Our mission is to provide superior training, access to cutting edge instrumentation, expertise in assay development and data analysis, and opportunities for cross-collaboration with other shared resources at HCC. CF has been located in the HCC Research Pavilion since September 2002. The laboratory consists of a 1000 ft2 laboratory dedicated to preparative and analytical flow cytometry. CF provides services to over 100 users within HCC. The current instrumentation includes a Beckman Coulter MoFlo Astrios high-speed cell sorter equipped with a Class II Biocontainment hood, two Becton Dickinson 15/18-color SORP Fortessa analyzers with custom high-power lasers, and a Becton Dickinson Accuri C6 4- color analyzer. Recent additions of a Sony MA900 cell sorter, also equipped with a Class II Biocontainment hood, and a Cytek Aurora, a spectral cytometer, have addressed the increasing demand for more access to state-of-the-art instrumentation. Education initiatives have expanded considerably, including a tiered system of user expertise, advanced education seminars on spectral cytometry, and user-operated cell sorting on the Sony MA900. The Specific Aims focus on providing access and training on existing equipment, integrating new equipment, and providing expert research staff and continuing education to users on new experimental methods.