PROJECT SUMMARY The Flow Cytometry Shared Resource (FC-SR) provides state-of-the-art flow cytometry and cell sorting services to the Stanford Cancer Institute (SCI) members. The FC-SR has two locations on the Stanford campus; (1) the primary site is within the Beckman Center for Genetics and Molecular Medicine on the main campus, and (2) a smaller satellite facility supports researchers at the nearby School of Medicine Technology and Innovation Park. In total, FC-SR maintains 7 flow analyzers, 1 mass cytometer, and 9 cell sorters maintained and operated by six full-time and two part-time staff members. The staff span three ‘generations’ of cytometrists with extensive knowledge and experience in both technical development of the instrumentation and development of flow cytometry applications. They promote quality research by providing extensive consultation for experiment design, including high parameter assay development, instrument use, and data analysis. Since the last review, the FC- SR continued to acquire new high-end instrumentation, with the most recent purchase of 2 high-parameter analyzer purchases, one of which was funded by an NIH Instrumentation Grant. Members of all programs regularly use the FS-SR, with the heaviest use coming from the Cancer Biology and Cancer Stem Cells and Cancer Immunotherapy programs. In 2020, 46% of users were SCI investigators. More than a quarter of all SCI labs use the sorting, analyzer, and educational/consult services each year, and the FC- SR has contributed to 57 cancer-focused publications (18 high-impact). The annual budget of the FC-SR is $1,536,654, yet the CCSG request is $115,133. Accordingly, the CI-SR leverages extensive institutional support and seeks only 7% from CCSG funds. The FC-SR is focused on two major aims: (1) to provide access to cutting- edge instrumentation for cell analysis and sorting and (2) to promote high-quality research using cytometric techniques, including the provision of high-level, cost-effective training and expertise and support development of new techniques and applications.