Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 11,252	$ 58,440
Short-term marketable securities	111,477	28,585
Prepaid expenses and other current assets	1,609	1,564
Total current assets	124,338	88,589
Property and equipment, net	14,841	9,783
Restricted cash	1,097	1,097
Other assets	64	230
Total assets	140,340	99,699
Current liabilities:
Accounts payable	2,380	2,679
Accrued expenses	5,034	4,823
Deferred revenue	268	444
Deferred rent	393	656
Capital lease obligations	266	425
Total current liabilities	8,341	9,027
Long-term liabilities:
Deferred revenue, net of current portion		668
Deferred rent, net of current portion	7,691	4,500
Capital lease obligations, net of current portion	210	466
Total long-term liabilities	7,901	5,634
Commitments and contingencies (Note 18)
Stockholders' Equity
Preferred stock, $0.001 par value 5,000,000 shares authorized, none issued and outstanding as of December 31, 2018 and December 31, 2017
Common stock, $0.001 par value 250,000,000 shares authorized as of December 31, 2018 and December 31, 2017. 25,401,479 shares issued and outstanding as of December 31, 2018 and 16,272,617 shares issued and outstanding as of December 31, 2017.	25	16
Additional paid-in capital	243,903	156,685
Accumulated other comprehensive loss	(65)	(9)
Accumulated deficit	(119,765)	(71,654)
Total stockholders' equity	124,098	85,038
Total liabilities and stockholders' equity	$ 140,340	$ 99,699

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).