The Fas- and FasL-deficient mice showed significantly decreased levels of IL-10 expression early during infection (3rd and 7th d.p.i) in comparison to wild-type mice (P ≤ 0.001) (Figure 4(d)), followed by significantly decreased mRNA levels of TGF-β1 at 7th and 10th d.p.i. This evidence concerns the gene TGFB1 and infection.