In contrast, SQ treatment of C5aR1 knockout mice with CDPI-02 had no effect against SQ infection with CA-MRSA up to 48 h post-challenge vs. inactive scCPDI-02 [24], indicating that prophylactic SQ treatment with CPDI-02 increases protection against SQ infection with CA-MRSA through the activation of C5aR1. The gene discussed is C5AR1; the disease is infection.