The University of Wisconsin Carbone Cancer Center (UWCCC) Flow Cytometry Laboratory (Flow Lab) is a heavily utilized shared service on the University of Wisconsin-Madison campus available to researchers who are members as well as non-members of the UWCCC. The impact of the Flow Lab on biomedical research infrastructure at UW-Madison is significant. This Shared Instrumentation Grant is a request for funds that cover 80% (remaining 20% supported by the institution) of the total cost of a BD LSR Fortessa" (Fortessa) instrument to further enhance the capability and the capacity of the Flow Lab. The addition of the Fortessa will alleviate the 2-3 week wait times currently experienced by our users allowing timely analysis of clinical research samples. It will provide high laser power for increased resolution of cellular subpopulations and excitation wavelengths (561nm and 355nm) necessary for detection of newly developed fluorescent markers, and will include a High-Throughput Sampler option for increased efficiency and screening capability. This instrument will provide redundancy when the existing 5-laser LSR is undergoing maintenance and/or repair. The experienced staff, well-established daily Quality Control Procedures, Online Scheduling System and Educational Programs allow for seamless integration of the Fortessa into the Flow Lab. The Fortessa cytometer will impact the development of novel treatment strategies for various human pathologies and increase our understanding of human biology. Funded projects by major and minor users benefiting by addition of the Fortessa include (i) clinical trials for development of a prostate cancer vaccine (Doug McNeel), (ii) immunotherapeutic agents for melanoma (Paul Sondel), (iii) mouse models for CMML (Jing Zhang), (iv) rat models for genetic modulation of mammary cancer (Michael Gould), (v) modulating immune responses in ovarian cancer (Manish Patankar), (vi) Graft versus Host disease in allogeneic bone marrow transplant patients with hematologic malignancies, (vii) effect of biobehavioral factors on immune function (Erin Costanzo), (viii) fibrogenesis in kidney disease (Arjung Djamali), (ix) hematopoietic stem cell maturation into cardiomyocytes (Sean Palecek), (x) ventilatory control due to effects of inflammation on neuronal cells (Jyoti Watters), (xi) effect of genetic mutations in a zinc transporter on sphodylocheiro dysplastic form of Ehlers- Danlos Syndrome (David Eide), (xii) immune maturation and regulation in farm and non-farm raised children to better understand wheezing illnesses (David Gern), (xiii) transcription factors in tumor suppression and DNA damage (Randall Tibbets), and (xiv) development of anti-fungal vaccines (Marcel W?thrich and Bruce Klein). Excellent institutional support in the form of 20% cost sharing of the total price of the Fortessa, salary support for trained technical staff, and the service agreement to maintain a fully functional and well-equipped cytometer will allow us to fulfill the research needs of major and minor users for the next 10 years.