Related Party Transactions	3 Months Ended
Mar. 31, 2013
Related Party Transactions	8. Related Party Transactions We have entered into several agreements with related parties in the ordinary course of business to license intellectual property and to procure administrative and research and development support services. These agreements include a Services Agreement with our founding companies Isis Pharmaceuticals and Alnylam Pharmaceuticals. Total costs incurred from services provided from Alnylam under the Services Agreement were $0.4 million for the three months ended March 31, 2013. Activities under the Services Agreement for the three months ended March 31, 2012 were immaterial.

Related Party Transactions

3 Months Ended

Mar. 31, 2013

8. Related Party Transactions

We have entered into several agreements with related parties in the ordinary course of business to license intellectual property and to procure administrative and research and development support services. These agreements include a Services Agreement with our founding companies Isis Pharmaceuticals and Alnylam Pharmaceuticals. Total costs incurred from services provided from Alnylam under the Services Agreement were $0.4 million for the three months ended March 31, 2013. Activities under the Services Agreement for the three months ended March 31, 2012 were immaterial.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

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Reference 9: http://www.xbrl.org/2003/role/presentationRef

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+ Details