CLDN1 and infection: Figure 7a and Supplementary Fig. 9 show a marked decrease in staining for claudin-1 in the PA14 + vehicle infection group that received no treatment (60.41 fluorescence intensity arbitrary units (AUs)), as compared to the mice that were infected with PA14 and received D88 (142.48 AUs), as well as compared to animals that were infected with the isogenic mvfR mutant strain (144.58 AUs).