The Gene Expression Core is dedicated to making molecular gene expression technology available to cancer center members in a user-friendly manner. We utilize oligonucleotide arrays, cDNA arrays and quantitative RNA methodologies to investigate the changes in gene expression. Affymetrix technology is used for the oligonucleotide arrays. The Affymetrix platform has a large number of products, all of which are supported by the Core, including expression arrays and SNP analysis. Custom spotted arrays are constructed from sequenceverified clones, selected oligonucleotide sets, as well as commercially available arrays from Agilent and CodeLink. Quantitation of selected genes is made possible using real time PCR. With these capabilities, the objectives of the Gene Expression Core facility are to: 1) Analyze gene expression using both oligonucleotide and cDNA arrays;2) Facilitate gene discovery;3) Accurately quantitate gene expression using real time PCR; 4) Provide support for data analysis and bioinformatics by our data mining tool and our cluster analysis capabilities. This facility has a commitment to utilizing a variety of approaches for expression analysis. This core was established in response to the technological advances in gene array, as well as the demand for high throughput expression analysis and genomic investigation to investigate pathogenesis, therapeutics, genetic susceptibility and gene discovery in cancer research. The informatics aspect is of paramount importance, and five distinct analysis programs, as well as a network, are used to store, share and analyze the data. The facility has the capability and flexibility to adapt as the field of array technology changes. These changes are translated into upgrading the facility and its services. More complex analysis of gene expression arrays is available to members through the Biostatistics/Bioinformatics Core. To date, the Core is one of the highest volume Affymetrix microarray facilities in academia in the country, having performed over 6366 microarrays including test arrays on 4816 samples over 5 years for nearly 160 investigators. On average, 75% of the user's are Cancer Center members. Data from the Core has been incorporated into over 100 published manuscripts to date. The Core is also partly supported by an NHLBI Microarray Center Consortium award to Dr. Geraci. This support has made it possible for the Core to double its capacity in the past year. Future directions of the Core include upgraded technologies and the use of high-throughput analysis in translational research.