Normalization of the phosphorylation of IκB, NFκB, p38 MAPK, and CREB (Fig 4E–4H) to account for observed baseline differences between P2X7R-/- and C57BL/6J mice revealed that intrinsic differences between the strains correlate with differential phosphorylation of inflammatory regulators, independent of infection. This evidence concerns the gene CREB1 and infection.