In contrast, pharmacological inhibition of C5aR1 signaling by its antagonist PMX-205 or deletion of C5aR1 is sufficient to attenuate the immunosuppressive microenvironment, suppress tumor growth, and reduce lung metastases [10, 11], highlighting the potential value of targeting C5aR1 for CRC treatment. Here, C5AR1 is linked to colorectal carcinoma.