In line with the increased alveolar-capillary permeability, histological scoring of the lungs 24 hours after infection with 5x105 CFU NCTC 7978 pneumococci revealed a significant increase in perivascular edema and pleuritis formation and a tendency towards increased necrosis formation and area of pneumonia affected lung tissue in myeloid KLF4 KO mice in comparison with KLF4 WT mice (Figures 2F–I and Supplementary Figure S3). Here, KLF4 is linked to susceptibility to pneumonia measurement.