SANTA CLARA, Calif. — Affymetrix, Inc. (Nasdaq:AFFX) announced today that the Institute for Pharmacogenomics and Individualized Therapy (IPIT) at the University of North Carolina in Chapel Hill is using the company’s DMET™ Plus biomarker panel to expand the Pharmacogenetics for Every Nation Initiative (PGENI). The PGENI’s mission is to help developing countries use genetic information to improve their drug dosing decision-making process.

Doctors understand that drug response and drug-related toxicity vary widely among patients suffering from common diseases. A “one-dose-fits-all” strategy is not ideal or cost-effective for most patients, particularly in developing countries. The cost of individual genetic testing will be prohibitive in these countries for some time, so the PGENI’s strategy is to integrate pharmacogenomics into public health decision making without placing an extra burden on sparse healthcare funds and technology infrastructure.1

The data gathered by PGENI researchers will help them analyze populations in the developing world for their response to most commonly used medications. The program will initially focus on Jordan, Mexico, India, China, Brazil, Ghana, and South Africa, and the university eventually plans to expand to more than 100 countries.

“By using the DMET panel, we can genotype the largest and most comprehensive set of key functional drug metabolism alleles within a single panel,” said Dr. Howard McLeod, principle investigator and leader of PGENI. “To accomplish this with other technologies would be inefficient, very labor intensive, require multiple techniques, and would produce compromised data quality.”

The DMET Plus biomarker panel contains markers in all FDA-validated genes2 and covers more than 90 percent of the current ADME Core markers as defined by the PharmaADME group. It offers 1,936 high-value, biologically relevant markers in 225 drug metabolism enzyme, transporter, and transferase genes. Together these features make the Affymetrix DMET panel the most comprehensive one targeting all functional variants within drug metabolism genes.

“Dr. McLeod is one of the foremost experts in pharmacogenomics. He has shown how DMET Plus products can be used to make genotype-related dosing recommendations and the potential power of this technology to be integrated into clinical practice,” said Kevin King, president and CEO of Affymetrix. “It is an honor for our product to be chosen to help governments make informed public health decisions using genetic information.”

For more information on the DMET Plus Reagent Kit, Arrays, and Software, please visit www.affymetrix.com/dmet.

1https://pgeni.unc.edu/who_we_are/who_we_are.php

2Frueh, F. W., et al. Pharmacogenomic biomarker information in drug labels approved by the United States Food and Drug Administration: prevalence of related drug use. Pharmacotherapy 28(8):992–998

About the UNC Institute for Pharmacogenomics and Individualized Therapy

IPIT is a collaborative effort between the UNC Eshelman School of Pharmacy and the School of Medicine, Gillings School of Global Public Health, and the School of Nursing, with substantial support from the Lineberger Comprehensive Cancer Center and the Carolina Center for Genome Sciences. Leadership in these key areas of research is fostered by the creation of contiguous office and laboratory space that bolsters collaborations and the development of comprehensive research investigations and treatment tools.

The mission of IPIT is to employ an interdisciplinary approach to tailor therapies and enable the delivery of individualized medical practice. IPIT also offers the services of facilities in molecular genomics, cellular phenotyping, and pharmacoinformatics to add to the excellent core facilities already existing at UNC. For more information, please visit: https://ipit.unc.edu/.

About Affymetrix

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 1,800 systems have been shipped around the world and more than 20,000 peer-reviewed papers have been published using the technology.

Affymetrix is headquartered in Santa Clara, Calif., and has manufacturing facilities in 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. These and other risk factors are discussed in Affymetrix’ Form 10-K for the year ended December 31, 2008, and other SEC reports for subsequent quarterly periods.