Developing Countries Sign up for Pharmacogenomics for Every Nation Initiative Using the Affymetrix DMET Plus Panel

SANTA CLARA, Calif.--(Business Wire)--
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.

1http://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: http://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.

Affymetrix Inc.
Media Contact:
Justin O`Kelly, 408-731-5991
Public Relations Manager
Investor Contact:
Doug Farrell, 408-731-5285
Vice President, Investor Relations

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