Gilead Sciences and the Institute of Organic Chemistry and Biochemistry (IOCB) Establish New Academic Research Centre in Prague; Donation by Gilead Honors Leadership of Dr. Antonin Holy in Antiviral Drug Discovery and Development

Gilead Sciences, Inc. (Nasdaq:GILD) today announced a
donation to The Institute of Organic Chemistry and Biochemistry at the
Academy of Sciences of the Czech Republic (IOCB) for the establishment
of a Gilead Sciences Research Centre. Gilead will provide a $1.1
million annual donation to IOCB for an initial five-year term to fund
the Centre's operations and ongoing research activities.
IOCB will use the donations to establish and support the Gilead
Sciences Research Centre, which will consist of selected research
groups led by the scientists at IOCB. In addition, Gilead and IOCB
will establish the Gilead Distinguished Chair in Medicinal Chemistry.
Dr. Antonin Holy, IOCB, will be the first to hold the position of
Distinguished Chair and will continue to lead research efforts in
nucleoside and nucleotide drug discovery. The operation of the
Research Centre will be governed by a Steering Committee and monitored
by an Advisory Board.
In 1991 and 1992, Gilead entered into license agreements with IOCB
and the Rega Institute for Medical Research, Katholic University in
Leuven, Belgium that cover a large number of nucleotide analogue
compounds and structures. Several of these nucleotide compounds
(specifically HPMPC, PMPA and PMEA) discovered through a collaborative
research effort between Dr. Antonin Holy and Dr. Erik DeClercq, Rega
Institute, were developed by Gilead, resulting in Vistide(R)
(cidofovir injection) for the treatment of CMV retinitis in AIDS
patients, Viread(R) (tenofovir disoproxil fumarate) for the treatment
of HIV infection and Hepsera(R) (adefovir dipivoxil) for the treatment
of chronic hepatitis B.
"The compounds that Gilead licensed from IOCB represent an
important component of our product portfolio and, most importantly,
have helped deliver new treatment options to hundreds of thousands of
patients suffering from HIV and chronic hepatitis B," said John C.
Martin, President and CEO, Gilead Sciences. "We are pleased to be able
to honor the contribution of Dr. Holy and the productive collaboration
between Gilead and IOCB over the years through this donation, which
will fuel IOCB's leading role in scientific research and drug
discovery."
"The scientific pursuit of new targets, new compounds and novel
mechanisms for identifying or treating diseases is our most important
priority," said Dr. Antonin Holy. "We have a long-standing and
productive relationship with Gilead, and we are deeply appreciative of
the company's support for this new Research Centre."
Today, Gilead and IOCB have also entered into a separate
arrangement under which Gilead will provide patent services to the
IOCB, and as part of this arrangement Gilead will have the first right
of refusal to license technologies in certain therapeutic areas from
IOCB.

About Gilead Sciences

Gilead Sciences is a biopharmaceutical company that discovers,
develops and commercializes innovative therapeutics in areas of unmet
medical need. The company's mission is to advance the care of patients
suffering from life-threatening diseases worldwide. Headquartered in
Foster City, California, Gilead has operations in North America,
Europe and Australia. For more information, please visit
www.gilead.com.

About IOCB

The Institute performs fundamental research in organic chemistry,
biochemistry and related disciplines oriented mostly to medicinal and
environmental applications. The Institute is involved in university
level of education and supervises diploma and PhD studies.

Forward-Looking Statement

This press release includes forward-looking statements, within the
meaning of the Private Securities Litigation Reform Act of 1995, that
are subject to risks, uncertainties and other factors. These risks,
uncertainties and other factors could cause actual results to differ
materially from those referred to in the forward-looking statements.
The reader is cautioned not to rely on these forward-looking
statements. For these and other risks Gilead directs its readers to
its Annual Report on Form 10-K for the year ended December 31, 2005
and the report on Form 10Q for the first quarter 2006 as filed with
the U.S. Securities and Exchange Commission. All forward-looking
statements are based on information currently available to Gilead and
Gilead assumes no obligation to update any such forward-looking
statements.