 Accordingly, the human leukocyte cell line, HL-60 promyelocytes (which do not respond to FMLP), was purposely differentiated to granulocytes (which do respond to FMLP) and used to partially purify and clone a gene that when transfected into FMLP-unresponsive cells bestowed responsiveness to this and other N-formyl oligopeptides.This receptor was initially named the formyl peptide receptor (i.e.FPR).