CASP8 and Yersinia infectious disease: Importantly, the presence of WT or Ripk3-/- cells in the Ripk3-/-Casp8-/- mixed BM chimeras provided protection from Yersinia infection, as the Ripk3-/-Casp8-/- mixed BM chimeras had similar bacterial burdens compared to mice that contained only wild-type or a mixture of Ripk3-/- and wild-type bone marrow (Fig 1G and S1F Fig).