Receptor for the chemotactic and inflammatory peptide anaphylatoxin C5a. The ligand interacts with at least two sites on the receptor: a high-affinity site on the extracellular N-terminus, and a second site in the transmembrane region which activates downstream signaling events. Receptor activation stimulates chemotaxis, granule enzyme release, intracellular calcium release and superoxide anion production.,C5AR1,C5A,C5AR,C5R1,CD88,Cancer,Signal Transduction,G protein signaling,G-Protein-Coupled Receptors(GPCR),Endocrine & Metabolism,Immunology & Inflammation,CD markers,Cell Intrinsic Innate Immunity Signaling Pathway,C5AR1