tokens: The three regions concerned are : 1 ) a region between -73 and -36 , which is the minimal element inducible by LPS or TNF-alpha ; 2 ) an element located between -181 and -73 , which appeared to regulate the response to IFN-gamma and TNF-alpha negatively ; and 3 ) a distal element upstream of -224 , which was inducible by IFN-gamma alone .