RSAD2 and infection: The differences in the requirement for the viperin SAM1 domain seen in our current study compared with previous results with DENV-1 and WNV may be due to (i) the level of expression of viperin through use of a tet-induction system compared with the transient viperin transfection system in the current study; (ii) the analysis of different markers of infection with viperin SAM1 reducing infectious DENV-1 release [13] but in our study not DENV-2 −ve strand RNA; and/or (iii) the use of DENV-1 compared to DENV-2 herein.