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CONSENT OF INDEPENDENT ACCOUNTANTS
We hereby consent to the incorporation by reference in the Biogen Idec Inc. Registration Statement on Form S-8 of our report dated February 14, 2003 relating to the financial statements of Biogen, Inc., which is included in the Biogen Idec Inc. Current Report on Form 8-K dated November 12, 2003.
/s/ PricewaterhouseCoopers LLP
Boston, Massachusetts
November 12, 2003
CONSENT OF INDEPENDENT ACCOUNTANTS