S100A9 and infection: Dissemination of E. coli from the urinary tract to the circulation was not significantly different between WT and S100A9 KO mice 24 and 48 hours after infection (number of positive blood cultures; WT vs. S100A9 KO mice, t = 24: 0/9 vs. 3/9, P = 0.06 and t = 48: 0/9 vs. 0/9, P = 1.00).