The identification of biomarkers of cancer risk, treatment response and progression, including genetic polymorphisms, epigenetic alterations, infectious agents and aberrant levels of proteins, hormones and nutrients has become an increasingly important aim of investigators with peer-reviewed funding at Fox Chase Cancer Center (FCCC), The Cancer Prevention Biomarker and Genotyping Facility (CPBGF) was established in 2001 as a developing Core Facility and provides a centralized resource for cost-effective genotyping services and biomarker assays to support research-based human population and mouse studies. Genotyping services include the analysis of polymorphic variation and mutations within normal or tumor DMA utilizing state-of-the-art instrumentation and technology. Assessment of host genotype and tissue-specific alterations in DNA sequence aids in identifying predictive genetic biomarkers of cancer risk and treatment response as well as surrogate endpoints for chemoprevention. Mouse genotyping services also aid researchers in the breeding and maintenance of their transgenic and knockout strains. In addition to genotyping, the Facility performs assays for the analysis of potential environmental and behavioral biomarkers of cancer risk (i.e., tobacco metabolites and bisphenol) as well as dietary factors, which can be measured in tissues and biofluids. This new Core Facility is directed by Cynthia Spittle, Ph.D. Since its inception in 2001, the Facility has provided services for a total of 18 FCCC investigators in six Research Programs in all three Divisions. In 2003, >94% of usage was from investigators with peer-reviewed funding. There has been >200% increase in the number of genotyping assays performed during the first three years of operation. The services provided by the CPBGF benefit clinicians, epidemiologists and behavioral scientists with interests in cancer prevention and pharmacogenetics research and basic scientists who utilize mouse models in their work. The demand for genotyping and biomarker analyses is expected to continue to grow over the next five years. The CPBGF offers distinctive and non-duplicative services that are a vital addition to the support offered to investigators with peer-reviewed funding. During the next five years, the CPBGF will expand its services, staffing, and infrastructure in a cost-effective manner in order to best meet the needs of investigators with peer-reviewed funding.