The first defined human FPR gene, FPR1 (www.uniprot.org/uniprot/P21462), was initially reported as a high affinity binding site on the surface of neutrophils for the prototypic N-formyl peptide formyl-methionine-leucine-phenylalanine (fMLF) and then its gene was cloned in 1990 from a differentiated HL-60 myeloid leukemia-cell cDNA library [7], [8]. Here, FPR1 is linked to myeloid leukemia.