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Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

The Board of Directors
NeoRx Corporation:

        We consent to the use of our reports with respect to the consolidated financial statements, management's assessment of the effectiveness of internal control over financial reporting and the effectiveness of internal control over financial reporting incorporated by reference herein and to the reference to our firm under the heading "Experts" in this prospectus.

        Our report dated March 28, 2005 contains an explanatory paragraph that states that the Company has suffered recurring losses, has had significant recurring negative cash flows from operations, and has an accumulated deficit that raise substantial doubt about its ability to continue as a going concern. The consolidated financial statements do not include any adjustments that might result from the outcome of that uncertainty.

/s/  KPMG LLP

Seattle, Washington
March 28, 2005

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Consent of Independent Registered Public Accounting Firm