IFNB1 and infection: As production of IFN-α was not significantly altered by loss of RIPK3 (Fig 2B), and as induction of ifnb1 mRNA (encoding IFN-β) after infection with PR8-ΔNS1 was mostly indistinguishable between ripk3+/+ and ripk3-/- MEFs (Fig 2C), these results suggest a modest post-transcriptional, kinase-independent role for RIPK3 in selective production of IFN-β after RNA virus infection of fibroblasts.