Other Financial Information

Marketable Securities

Our marketable securities are comprised of the following (in thousands):



	As of September 30, 2013
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
U.S. treasury securities	$	35,002	$	3	$	—		$	35,005
Certificates of deposit	10,496		—		(6		)	10,490
Mutual funds	230		236		—			466
Total marketable securities	$	45,728	$	239	$	(6	)	$	45,961



	As of December 31, 2012
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
U.S. treasury securities	$	40,019	$	8	$	(12	)	$	40,015
Certificates of deposit	11,746		1		(9		)	11,738
Mutual funds	224		163		—			387
Total marketable securities	$	51,989	$	172	$	(21	)	$	52,140

As of September 30, 2013 and December 31, 2012, gross unrealized losses on marketable securities were insignificant. There were no impairments considered other-than-temporary for the periods presented, as it is management's intention and ability to hold the securities until maturity or a recovery of the cost basis or recovery of fair value.

There were no sales of marketable securities during all periods presented and, therefore, there were no gross realized gains or losses on sales of marketable securities during all periods presented. As of September 30, 2013, all of our marketable securities were due within one year.

Inventories

Inventories consist of the following (in thousands):



	September 30, 2013		December 31, 2012
Raw materials	$	17,802	$	8,317
Work in process	949		655
Finished goods	1,483		1,598
Total	$	20,234	$	10,570

Inventories are shown net of obsolete and excess reserves of $0.8 million and $0.5 million at September 30, 2013 and December 31, 2012, respectively.

Property, Equipment and Leasehold Improvements

Property, equipment and leasehold improvements and related accumulated depreciation and amortization are as follows (in thousands):



	September 30, 2013			December 31, 2012
Building and improvements	$	8,687		$	8,660
Laboratory equipment	48,362			42,846
Leasehold improvements	8,122			7,950
Office furniture and equipment	21,109			19,537
	86,280			78,993
Less accumulated depreciation and amortization	(56,373		)	(45,499		)
Total	$	29,907		$	33,494

Depreciation expense for the nine months ended September 30, 2013 and 2012 was $11.0 million and $7.4 million, respectively. Assets recorded under capital leases of $0.4 million and $0.4 million are included in the office furniture and equipment balance at September 30, 2013 and December 31, 2012, respectively. Depreciation of assets under capital leases is included in depreciation expense.

Accrued Expenses

Accrued expenses consist of the following significant items (in thousands):



	September 30, 2013		December 31, 2012
Accrued royalties, licenses, and collaboration payments	$	10,822	$	5,338
Accrued compensation and related taxes	6,485		11,409
Accrued professional fees and consulting	3,147		2,511
Other	4,378		5,249
Total	$	24,832	$	24,507

Stockholders' Equity (Deficit)

Changes in shares of common stock outstanding and total stockholders' equity (deficit) are as follows (in thousands):



	Shares of Common Stock Outstanding	Total Stockholders' Equity (Deficit)
Balance as of December 31, 2012	114,787	$	48,007
Net loss	—	(88,531		)
Stock-based compensation	—	7,962
Shares issued or vested under employee stock plans	930	1,372
Unrealized gain on available-for-sale securities	—	73
Foreign currency translation adjustment	—	88
Balance as of September 30, 2013	115,717	$	(31,029	)

Accumulated Other Comprehensive Income

Comprehensive loss and its components encompasses all changes in equity other than those with stockholders, and includes net loss, unrealized gains and losses on our available-for-sale marketable securities, and foreign currency translation gains and losses.

Changes in accumulated other comprehensive income by component are as follows (in thousands):



	Unrealized Net Gains on Available-for-Sale Securities, net of Deferred Taxes		Foreign Currency Translation Adjustments		Total
Balance as of December 31, 2012	$	97	$	326	$	423
Other comprehensive income	73		88		161
Balance as of September 30, 2013	$	170	$	414	$	584