TNF and coinfection: We find that whereas co-infection with wild-type (WT) vaccinia or E3LΔ26C virus (in which the E3 C-terminal dsRNA binding domain is deleted) significantly attenuated the induction of IFN-α and TNF by myxoma virus or Heat-VAC, co-infection with vaccinia mutant ΔE3L (E3 null) or E3LΔ83N (in which the E3 N-terminal Z-DNA/RNA binding domain is deleted) only partially reduced IFN-α and TNF induction.