Thus, A144E heterozygous mice, obtained by crossing WT mice with homozygous Tnfrsf13b A144E mice, frequently resist infection or produce 20-fold less CFUs than WT littermates, and Tnfrsf13b A144E/A144E and Tnfrsf13b-KO mice, produced and backcrossed to C57BL/6 independently, are resistant. The gene discussed is TNFRSF13B; the disease is infection.