It’s a GAAP timing issue. Congress did not extend the R&D tax credit (and make it permanent and retroactive to 1/1/15) until Dec 2015, by which time ENTA had closed the books on FY2015 (which ended 9/30/15). So, for GAAP purposes, ENTA booked the actual cash-tax benefit of the 2015 R&D tax credit in FY2016.