Formyl peptide receptor-like 1 (FPRL1) is a seven transmembrane domain, G protein-coupled receptor that interacts with a variety of exogenous and host-derived agonists. In order to identify domains crucial for ligand recog-nition by FPRL1, we used chimeric receptors with segments in FPRL1 replaced by corresponding amino acid sequences derived from the proto-type formyl peptide receptor FPR. The chimeric receptors were stably transfected into human embryonic kidney epithelial cells and the capacity of the cells to migrate in response to formyl peptide receptor agonists was evaluated. .