Since FPR2/Fpr2 is also highly expressed by phagocytic cells and is involved in their recruitment to inflamed tissues [49,50] the higher titers of C. rodentium found in the spleen of Fpr2−/− mice may in part be due to poor immunosurveillance of invading bacteria in extraintestinal tissues early during infection, before any C. rodentium-specific IgG antibodies are produced to support clearance of the pathogens [51]. The gene discussed is FPR2; the disease is infection.