Major Customers, Partnerships and Strategic Alliances (Tables)

6 Months Ended

Jun. 30, 2015

Revenues recognized under the agreement with Biogen for the three and six months ended June 30, 2015 and 2014 are as follows (in thousands):

	Three months ended				Six months ended
	June 30,				June 30,
	2015		2014		2015		2014
Revenue related to Biogen Collaboration:
Recognition of upfront fee	$	1,540	$	1,540	$	3,063	$	2,200
Research services		1,701		1,338		3,233		1,761
Total	$	3,241	$	2,878	$	6,296	$	3,961

Revenues recognized under the agreement with Shire for the three and six months ended June 30, 2015 and 2014, were as follows (in thousands):

	Three months ended				Six months ended
	June 30,				June 30,
	2015		2014		2015		2014
Revenue related to Shire Collaboration:
Recognition of upfront fee	$	542	$	542	$	1,083	$	1,083
Research services		3,894		5,930		8,416		10,910
Total	$	4,436	$	6,472	$	9,499	$	11,993

Revenues recognized under the agreement with Sigma for the three and six months ended June 30, 2015 and 2014, were as follows (in thousands):

	Three months ended				Six months ended
	June 30,				June 30,
	2015		2014		2015		2014
Revenue related to Sigma Collaboration:
Royalty revenues	$	28	$	97	$	293	$	203
License fee revenues		21		—		4,277		179
Total	$	49	$	97	$	4,570	$	382