PPIB and influenza: While all Rag−/− mice eventually succumb to influenza infection, Figure 2a demonstrates that infected Rag−/−(129) mice, like their wild-type (wt) counterparts, lost weight and reached clinical end point more rapidly than Rag−/−(B6) mice and had higher concentrations of IFNα, -β and -λ in their BAL (Fig. 2c).