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STOCK OPTION PLANS (Details)
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Expected volatility 109.00% 111.00% 109.00%
Expected term 5 years 5 years 5 years
Risk-free interest rate 2.62% 1.81% 1.10%
Expected dividend yield 0.00% 0.00% 0.00%