KC levels increased to a peak value by day 8 post-infection and remained significantly higher in ChemR23−/− mice compared to WT mice at day 9 (86.4±20.5 versus 28.3±2.2 pg/ml respectively, p<0.01) and day 10 post-infection (50.3±5.4 versus 26.5±3.6 pg/ml respectively, p<0.01) (Figure 4B). This evidence concerns the gene CALCA and infection.