Supplementary Balance Sheet Information

Short-term Investments

The following table sets forth the composition of short-term investments as of December 31, 2016. No such investments existed as of December 31, 2015.



				Unrealized
	Maturity in Years	Cost		Gains		Losses			Fair Value

Corporate debt securities	Less than 1 year	$	14,165,915	$	44	$	(5,273	)	$	14,160,686
Commercial paper	Less than 1 year	1,195,444		—		—			1,195,444
U.S. treasury securities	Less than 1 year	8,625,728		330		(4,166		)	8,621,892
Total Investment		$	23,987,087	$	374	$	(9,439	)	$	23,978,022

Property and Equipment

Fixed assets consist of laboratory, testing and computer equipment and fixtures stated at cost. Depreciation and amortization expense for the years ended December 31, 2016, 2015, and 2014 was $969,833, $378,711, and $234,813, respectively. Property and equipment consisted of the following:



	As of December 31,
	2016			2015
Furniture and office equipment	$	1,144,741		$	1,264,547
Leasehold improvements	1,994,514			39,401
Laboratory equipment	2,449,645			2,241,413
	5,588,900			3,545,361
Less—accumulated depreciation and amortization	(1,761,985		)	(854,782		)
Property and equipment, net	$	3,826,915		$	2,690,579

Accrued Liabilities

Accrued liabilities consisted of the following:



	As of December 31,
	2016		2015
Accrued compensation	$	2,203,876	$	896,404
Accrued research agreements	736,199		386,267
Accrued professional fees	421,314		—
Other accrued liabilities	659,976		621,126
Total accrued liabilities	$	4,021,365	$	1,903,797