C5AR1 and Sepsis: However, Ward's group in USA reported opposite findings using a mouse model of cecal ligation and puncture (CLP), which induces polymicrobial sepsis.In “mid-grade” sepsis (30–40% survival), blockade or absence of either C5a receptors, C5ar or C5l2, greatly improved survival and attenuated the buildup of proinflammatory mediators in plasma [21].