The formyl peptide receptor (FPR) was defined pharmacologically in 1976 as a high affinity binding site on the surface of neutrophils for the peptide N-formyl-methionine-leucine-phenylalanine (fMLF). FPR was cloned in 1990 and the cDNA used as a probe to identify two additional genes, FPRL1 and FPRL2. The three genes for a cluster on 19q13.3. All are coupled to the Gi family of G proteins.
All 3 receptors can be activated by formyl peptides but also display affinities for a range of structurally diverse ligands.