Exhibit 99.1


 Geron Corporation Appoints Charles Homcy to Its Board of Directors


    MENLO PARK, Calif.--(BUSINESS WIRE)--July 19, 2005--Geron
Corporation (Nasdaq: GERN) announced today the appointment of Charles
J. Homcy, M.D., to its board of directors.
    Dr. Homcy is currently the President and Chief Executive Officer
of Portola Pharmaceuticals, a privately held biotechnology firm
focused on developing novel cardiovascular therapies. Dr. Homcy holds
A.B. and M.D. degrees from Johns Hopkins University. He has held
academic appointments in clinical medicine at Harvard Medical School,
Columbia University College of Physicians and Surgeons, and the
University of California, San Francisco. He has served on the
editorial boards of many of the leading scientific cardiovascular
journals. His industry experience includes past executive positions
with American Cyanamid, COR Therapeutics and Millennium
Pharmaceuticals as well as current board membership on several
biopharmaceutical companies. He is the author of over 135 original
publications in the field of molecular and clinical cardiology.
    "I am pleased to welcome Dr. Homcy to our board of directors,"
said Thomas Okarma, Ph.D., M.D., Geron's president and chief executive
officer. "Charles brings a wealth of product development experience to
our board as we focus on the clinical development of our Oncology and
Stem Cell products."
    "I am pleased to become a part of the Geron team," said Dr. Homcy.
"Their exciting portfolio of clinical stage cancer products that
target telomerase and cell therapies based on embryonic stem cells
represents some of the most innovative approaches to treating cancer
and chronic degenerative diseases that I know. I look forward to
helping the company accelerate its progress in bringing these
technologies to patients."
    Geron is a biopharmaceutical company developing and
commercializing three groups of products: i) therapeutic products for
oncology that target telomerase; ii) pharmaceuticals that activate
telomerase in tissues impacted by senescence, injury or degenerative
disease; and iii) cell-based therapies derived from its human
embryonic stem cell platform for applications in multiple chronic
diseases.

    This news release may contain forward-looking statements made
pursuant to the "safe harbor" provisions of the Private Securities
Litigation Reform Act of 1995. Investors are cautioned that such
forward-looking statements in this press release regarding potential
applications of Geron's technologies constitute forward-looking
statements that involve risks and uncertainties, including, without
limitation, risks inherent in the development and commercialization of
potential products, need for future capital and maintenance of our
intellectual property rights. Actual results may differ materially
from the results anticipated in these forward-looking statements.
Additional information on potential factors that could affect our
results and other risks and uncertainties are detailed from time to
time in Geron's periodic reports, including the quarterly report on
Form 10-Q for the quarter ended March 31, 2005.


    CONTACT: Geron Corporation
             David L. Greenwood, 650-473-7765