In addition increased levels of Ip10, Irf1, Stat1, Icsbp, at day 1 post infection in the blood of Ifnar1-/- as compared to the WT mice is in keeping with type I IFN inhibition of Th1 responses and could explain the subsequent reduction in bacterial load in the Ifnar1-/- infected mice. This evidence concerns the gene CXCL10 and infection.