A difference in percentages of Ly6Chi/Ly6C cells and in the size of the Ly6Chi monocyte population was found only prior to infection: During Orientia infection, as assessed on days 10, 14, 17 and 21 p.i., CCR2-/- mice showed no significant differences to the wildtype regarding the percentages of Ly6Chi/Ly6C+ cells, and they also expanded absolute numbers of CD11b+ Ly6Chi cells to the same extent as C57BL/6 mice (Figures S4A, B). This evidence concerns the gene ITGAM and infection.