In mouse malaria, we have observed that P. y. yoelii 17XNL–infected, basophil-depleted mice exhibited significantly increased intestinal permeability throughout the course of infection (15), whereas mice with basophils lacking IL-18R [baso IL-18R (−)] presented increased intestinal permeability only at day 4 postinfection (PI) (16) relative to their genotype controls. This evidence concerns the gene IL18R1 and infection.