AFFX Affymetrix, Inc.

Affymetrix Inc. (Nasdaq:AFFX) announced today that the Wellcome Trust Sanger Institute has developed a catalog of structural genomic changes in almost 800 cancer cell lines using the company�s Genome-Wide Human SNP Array 6.0. Cancer cell lines are invaluable reagents in analyzing the molecular biology of the disease as well as important tools in developing new healing methods. The core set of cancer cell lines developed by the Cancer Genome Project includes samples from most types of human cancer. Combined with more than 400 normal control samples, nearly 1,250 were analyzed using Affymetrix technology. The SNP Array 6.0 features more than 1.8 million markers for genetic variation, including more than 906,600 single nucleotide polymorphisms (SNPs) and more than 946,000 probes for the detection of copy number variation. The team from the Wellcome Trust Sanger Institute was able to map out the genomic regions of each sample, focusing on the alterations that occurred during the genesis of the cancer. These structural alterations can inactivate genes, increase gene activity or, more rarely, lead to gene products possessing new properties. "Previously, using an earlier version of the current array, we developed maps of structural variation at lower resolution," said Dr Graham Bignell, project leader at the Wellcome Trust Sanger Institute. "The new dataset provides a much more refined view of the changes that have occurred in these samples, as it represents a 180-fold increase in resolution. When viewed across nearly 800 samples, these maps give a remarkable insight into the ravages of the genome induced during cancer development." As part of the ongoing study within this series of cancer cell lines, mutations in more than 60 known cancer genes are being characterized and all data is being made publicly available on the Wellcome Trust Sanger Institute�s COSMIC website. �With these discoveries, the Wellcome Trust Sanger Institute enhances its reputation at the forefront of understanding the genomic changes that occur in cells as they progress towards cancer,� said Kevin King, president of Affymetrix. �The ability of the SNP Array 6.0 to detect copy number changes is advancing our understanding of the disease and ultimately enabling scientists to make clearer diagnoses and treatment choices.� About Affymetrix Affymetrix GeneChip� microarray technology is the industry-standard tool for analyzing complex genetic information. After inventing microarray technology in the late 1980s, Affymetrix scientists have been dedicated to developing innovative products that provide researchers with a more complete view of the genome. These products continue to accelerate genetic research and enable scientists to develop diagnostics and tailor treatments for individual patients by identifying and measuring the genetic information associated with complex diseases. Today, Affymetrix technology is used by the world�s top pharmaceutical, diagnostic and biotechnology companies, as well as leading academic, government and not-for-profit research institutes. More than 1,700 systems have been shipped around the world and more than 13,000 peer-reviewed papers have been published using the technology. Affymetrix is headquartered in Santa Clara, Calif., and has manufacturing facilities in Sacramento, Calif., Cleveland, Ohio, and Singapore. The company has about 1,100 employees worldwide and maintains sales and distribution operations across Europe and Asia. For more information about Affymetrix, please visit the company�s website at www.affymetrix.com. Forward-looking Statements All statements in this press release that are not historical are �forward-looking statements� within the meaning of Section 21E of the Securities Exchange Act as amended, including statements regarding Affymetrix� �expectations,� �beliefs,� �hopes,� �intentions,� �strategies� or the like. Such statements are subject to risks and uncertainties that could cause actual results to differ materially for Affymetrix from those projected, including, but not limited to: risks and uncertainties relating to commercial success of the agreement with the Wellcome Trust Sanger Institute discussed in this press release; risks of the company�s ability to achieve and sustain higher levels of revenue, higher gross margins and reduced operating expenses; uncertainties related to technological approaches, manufacturing and product development; personnel retention; uncertainties related to cost and pricing of Affymetrix products; dependence on collaborative partners; uncertainties related to sole-source suppliers; risks associated with past and future acquisitions; uncertainties relating to FDA and other regulatory approvals; competition; risks relating to intellectual property of others and the uncertainties of patent protection and litigation. These and other risk factors are discussed in Affymetrix� Form 10-K for the year ended December 31, 2007, and other SEC reports, including its Quarterly Reports on Form 10-Q for subsequent quarterly periods. Affymetrix expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in Affymetrix� expectations with regard thereto or any change in events, conditions or circumstances on which any such statements are based. NOTE: Affymetrix�, the Affymetrix logo and GeneChip� are registered trademarks owned or used by Affymetrix Inc.