Howard W. Robin, CEO of Sirna Therapeutics, Inc.,
Rings The NASDAQ Stock Market Opening Bell

Wednesday, April 5, 2006
at NASDAQ's MarketSite
in New York City.

Sirna Therapeutics, Inc.

Howard W. Robin, CEO of Sirna Therapeutics, Inc., presides over the opening bell to celebrate the Company's recent announcements on its respiratory collaboration with GlaxoSmithKline and U.S. patent issuance. Sirna Therapeutics is a clinical-stage biotechnology company developing RNAi-based therapies for serious diseases and conditions, including age-related macular degeneration (AMD), hepatitis B and C, dermatology, asthma, Huntington's disease, diabetes and oncology. Sirna Therapeutics completed its Phase 1 clinical trial for Sirna-027 in AMD in 2005 and with its strategic partner, Allergan, Inc., will move Sirna-027 into Phase 2 clinical trials in 2006.

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