Note 2 - Summary of Significant Accounting Policies (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2015

Dec. 31, 2014

Accounting Policies [Abstract]

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	September 30,
	2015		2014
Stock options to purchase common stock		3,352,783		2,294,534
Warrants to purchase common stock		2,864,823		-
Rights to common stock		-		956,354

	Year Ended December 31,
	2014		2013
Convertible preferred stock		-		195,062,650
Warrants to purchase convertible preferred stock		-		16,680,324
Stock options to purchase common stock		2,291,783		363,413
Warrants to purchase common stock		1,793,887		-
Rights to common stock		566,038		-