CASP8 and infection: Surprisingly, when Triton-X solubilized protein lysates from WT BMDM mock-treated or infected with either virus were immunoprecipitated with anti-FADD sera, ∆M36 infection (14 hpi) had no impact on the basal FADD-CASP8 complex detected in mock-treated cells (Figure 2F left panel), a result reminiscent of evaluations performed at 12 hpi [33].