RNASEL and infection: As expected, the two avian (dUBL and oUBL) and two mammalian (hUBL and mUbl) truncations failed to synthesize 2–5As (data not shown), induce rRNA degradation, and change the expression of RNase L and genes related to IFN signaling when treated with pIC or infection with H5N1 virus (DK/49, GS/65, CK/0513, or PR8), thus failing to inhibit H5N1 virus replication in DF1 and DF1OASL−/− or A549 cells (Figure S9 in Supplementary Material).