9. Commitments and Contingencies

Commitments

The Company’s operating lease obligations as of December 31, 2017 relate solely to the leasing of office space in a building at 395 Oyster Point Boulevard in South San Francisco, California, which is currently the Company’s headquarters. In January 2014, a lease for 15,378 square feet was entered into with an expiry date of April 30, 2015. In June 2014, the lease was amended to extend the expiration date to June 30, 2015, and to add 6,105 square feet of additional office space within the same building. The lease has been amended in January 2015 and September 2015 to extend the expiration date to December 31, 2016 and in September 2016, respectively and in May 2016, the lease was again amended to extend the expiration date to June 30, 2018. The lease was last amended in December 2017 to remove the 6,105 square feet of additional office space added in June 2014 and to extend the expiration date to June 30, 2021, with an option to extend the lease for two additional years.

Aggregate non-cancelable future minimum rental payments under operating leases as of December 31, 2017, were as follows (in thousands):

Year Ending December 31,	Payments
2018	$	514
2019	$	562
2020	$	579
2021	$	294
Total rental payments	$	1,949

The Company recognizes rent expense on a straight-line basis. The Company recorded rent expense of $0.7 million, $0.6 million and $0.5 million for the years ended December 31, 2017, 2016 and 2015, respectively.

Contingencies

From time to time, the Company may be involved in legal proceedings, as well as demands, claims and threatened litigation, which arise in the normal course of its business or otherwise. The ultimate outcome of any litigation is uncertain and unfavorable outcomes could have a negative impact on the Company’s results of operations and financial condition. Regardless of outcome, litigation can have an adverse impact on the Company because of the defense costs, diversion of management resources and other factors. The Company is not currently involved in any material legal proceedings.