C5AR2 (GPR77, C5L2) has been described as a receptor for the chemotactic and inflammatory peptides anaphylatoxin C5a, C4a and C3a and even their des-arginated derivatives. Highest binding affinity was for C3a-desArg, also called Acylation Stimulating Protein (ASP), produced from C3a following arginine removal by carboxypeptidases. Binding of C3a and its derivatives has been disputed (Johswich et al. 2006) leading to suggestions that this receptor may be a C5a scavenger. It is weakly coupled to G(i)-mediated signaling pathways and believed to function primarily as a decoy receptor though it can interact with beta arrestin (Van Lith et al. 2009).