C3 and bacterial infectious disease: Similar to our finding that c3a.1−/− zebrafish have impaired survival to bacterial infection, mice deficient in either C3 or the C3A receptor have increased susceptibility to septic arthritis38, and mice with C3A over-activation induced by deletion of the scavenger carboxypeptidase B2 displayed a survival benefit in the context of polymicrobial sepsis39, confirming a specific, protective role for C3A in infectious inflammatory contexts.