These findings suggest that while the absence of C3 does not influence disease severity, it does increase kidney colonization by L. interrogans in C57BL/6J mice at 30 d.p.i. Recently, our group demonstrated that during the early stages of infection with L. interrogans serovar Kennewicki strain Pomona Fromm, leptospiral loads were significantly higher, in the absence of C3, in the kidney, liver, and spleen at 3 d.p.i., and in the urine at 6 d.p.i. compared to WT-infected mice (22). The gene discussed is C3; the disease is infection.