Note 6 — Leases

Capital Leases

We lease office space at 201 Industrial Road in San Carlos, California under a capital lease arrangement. Under the terms of the lease, rent increases up to 3% annually and the lease termination date is October 5, 2016. As of November 29, 2010, we ceased use of this space as a result of the relocation of our San Carlos operations and corporate headquarters to San Francisco, California. As of April 2013, we had subleased all of the San Carlos facility and our future minimum rental receipts under these subleases total $2.1 million as of December 31, 2015.

In addition to our San Carlos capital lease, we have purchased certain manufacturing equipment under capital leases. As of December 31, 2015 and 2014, the gross amount of assets recorded under capital leases was $5.1 million and $2.7 million, respectively, and the recorded value of these assets, net of depreciation, was $3.2 million and $1.2 million, respectively.

Future minimum payments for our capital leases at December 31, 2015 are as follows (in thousands):

Years ending December 31,
2016	$	5,135
2017		1,043
2018		72
Total minimum payments required		6,250
Less: amount representing interest		(421	)
Present value of future minimum lease payments		5,829
Less: current portion		(4,756	)
Capital lease obligation, less current portion	$	1,073

Operating Lease

On September 30, 2009, we entered into an operating sublease (Sublease) with Pfizer, Inc. for a 126,285 square foot facility located in San Francisco, California (Mission Bay Facility). Under the terms of the Sublease, we began making non-cancelable lease payments in 2014, after the expiration of our free rent period on August 1, 2014. The Sublease term is 114 months, commencing in August 2010 and terminating on January 31, 2020. Monthly base rent will escalate over the term of the sublease at various intervals. In addition, throughout the term of the Sublease, we are responsible for paying certain costs and expenses specified in the Sublease, including insurance costs and a pro rata share of operating expenses and applicable taxes for the Mission Bay Facility.

Our future minimum lease payments for our operating leases at December 31, 2015 are as follows (in thousands):

Years ending December 31,
2016	$	4,892
2017		5,037
2018		5,187
2019		5,344
2020		452
Total future minimum lease payments	$	20,912

We recognize rent expense on a straight-line basis over the lease period. For the years ended December 31, 2015, 2014, and 2013, rent expense for all of our operating leases, which primarily consists of our Mission Bay Facility, was approximately $3.2 million, $3.2 million, and $2.9 million, respectively. As of December 31, 2015 and 2014, we had total deferred rent balances of $8.5 million and $8.7 million, respectively, which are recorded in other current and other long-term liabilities in our Consolidated Balance Sheets.