As Of	Filer	Filing¹	For·On·As	Docs:Size	Issuer		Filing Agent

12/21/06  Sequoia Technology Partners X LP  4          10% Owner²  2:25K  Isilon Systems, Inc.              DONNELLEY FIN… File16/FA 
          Goguen Michael L
          Leone Douglas M
          Moritz Michael J
          SC X Management LLC
          Sequoia Capital X
          Sequoia Capital X Principals Fund LLC
12/14/06  Moritz Michael J                  3          10% Owner²  2:18K  Isilon Systems, Inc.              DONNELLEY FIN… File16/FA 
          Goguen Michael L
          Leone Douglas M
          SC X Management LLC
          Sequoia Capital X
          Sequoia Capital X Principals Fund LLC
          Sequoia Technology Partners X LP

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¹	Filing/Form Types:
	3	Initial Statement of Beneficial Ownership of Securities by an Insider — Form 3 { The Filer is an Insider² of the Issuer }.
	4	Statement of Changes in Beneficial Ownership of Securities by an Insider — Form 4 { The Filer is an Insider² of the Issuer }.
²	Insider:  The Filer is a Director, Officer, 10% Owner and/or Other “insider” of the Issuer.