STAT1 and infection: Quantification of viral RNA levels showed that Stat1-/- mice displayed overall significantly higher viral burdens when compared with Stat1+/- littermates over the entire gastrointestinal tract, in Peyer’s patches (PP) and mesenteric lymph nodes (MLN), as well as in the spleen and liver only at 3 days post-infection (S1B–S1J Fig).