CCR1 and infection: For this to be plausible, (a) the receptor should be expressed on the surface of blood neutrophils (before the cells enter into the kidney) late after infection, and (b) the Ccr1-targeting chemokines should be induced in the kidney at the same time in order to generate a chemokine concentration gradient capable of recruiting Ccr1+ blood neutrophils into the kidney via mediating activation, firm adhesion and transmigration of neutrophils on the endothelial surface together with adhesion molecules [22].