Lin, D. C.-H et al. (J. Biol. Chem. 2002)
cloned and identified two human orthologs of mouse receptor Gpr73 (which is designated as hGPR73a and hGPR73b)which could be activated by prokineticins/endocrine gland vascular endothelial growth factor. Also, Masuda Y. et al
found that EG-VEGF/prokineticins are possible ligands for two orphan G-protein-coupled receptors EG-VEGF/PK-R1 and PK-R2.