Inventories

Inventories consist of the following:



	As of December 31,
	2015		2014
Raw materials	$	59,151	$	10,923
Work-in-process	132,068		73,519
Finished goods	11,197		10,768
Deferred costs	36,162		33,651
	$	238,578	$	128,861

Deferred costs represent the costs of product manufactured and shipped to the Company's collaborators for which recognition of revenue has been deferred (see Note 1). In 2015, 2014, and 2013, cost of goods sold included inventory write-downs and reserves totaling $10.6 million, $6.0 million, and $9.1 million, respectively.