In mice, transcript levels of Tgfb1 after MHV68 infection or bleomycin treatment showed comparable levels between Cyb5r3fl/fl and Cyb5r3 SPC–KO mice (Figure 2E and Figure 3E); however, relative expression of TGF-β1 target genes after injury was significantly different in the fl/fl or SPC-KO mice (Figure 2, F and G; Figure 3F; and Supplemental Figure 6C). Here, SFTPC is linked to infection.