The potential function of the M3 chemokine-binding protein in modulation of Scgb1a1 and Bpifa1 expression is interesting, but likely to be complex, and made more so by the M3-deficient virus being less pathogenic than vM3.MR, and hence, harboring a much higher viral load in the lung.15 Modulation of Scgb1a1 and Bpifa1 expression after MHV-68 infection clearly suggests a role for these factors in the host response. Here, BPIFA1 is linked to infection.