As an antithesis to sublethal IAV infection, lethal infection causes the accumulation of pDCs in DLNs with enhanced expression of Fas ligand (FasL) [147, 148] which engages with Fas, a membrane protein of the death receptor family [149] expressed on IAV-specific CD8+ T cells eliminating them via Fas-mediated apoptosis [147, 148]. This evidence concerns the gene FAS and infection.