C3 and infection: Having said that, we would like to point out that the severity of infection in C5aR1-/- mice was comparatively less than in C3-/- mice (see mortality at 1x105 doses of conidia in Figure 1B and Figure 5; both mice on BALB/c background), and therefore signaling through the C5aR1 receptor is only partially responsible for providing complement-mediated protection.