In our work we found that the lungs of Fas (−) and FasL (−) mice mobilized significantly less total numbers of CD4+ T cells at 3rd and 14th day of ECTV infection in comparison to wild-type mice and the total numbers of CD4+ T cells positive for IFN-γ were significantly lower during the whole infection period (Figure 3). The gene discussed is FAS; the disease is infection.