CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)	Mar. 31, 2018	Dec. 31, 2017
CURRENT ASSETS
Cash and cash equivalents	$ 7,169,262	$ 6,140,135
Marketable securities	5,995,380	7,984,800
Restricted cash	619,427	742,002
Grant receivable	306,750	344,575
Prepaid expenses and other current assets	522,346	501,164
TOTAL CURRENT ASSETS	14,613,165	15,712,676
PROPERTY AND EQUIPMENT, net	535,241	372,096
OTHER ASSETS
Intangible assets, net of accumulated amortization of $177,453 and $166,634, respectively	82,229	93,048
Other assets	157,787	95,969
TOTAL ASSETS	15,388,422	16,273,789
CURRENT LIABILITIES
Accounts payable and accrued expenses	1,408,338	1,496,251
Accounts payable and accrued expenses, related party	69,561	174,424
TOTAL CURRENT LIABILITIES	1,477,899	1,670,675
LONG-TERM LIABILITIES
CIRM liability	3,376,259	3,376,259
TOTAL LONG-TERM LIABILITIES	3,376,259	3,376,259
TOTAL LIABILITIES	4,854,158	5,046,934
COMMITMENTS AND CONTINGENCIES (NOTE 7)
STOCKHOLDERS' EQUITY
Preferred stock, $0.001 par value, 5,000,000 shares authorized, none issued and outstanding	0	0
Common stock, $0.001 par value, 50,000,000 shares authorized, 27,970,879 and 26,270,491 shares issued and outstanding, respectively	27,971	26,271
Additional paid-in capital	65,705,313	62,736,783
Accumulated other comprehensive income	20,329	11,620
Accumulated deficit	(55,219,349)	(51,547,819)
TOTAL STOCKHOLDERS' EQUITY	10,534,264	11,226,855
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 15,388,422	$ 16,273,789