There are provided non-human primate and rat GPR103 genes and proteins and a compound evaluation method employing the genes or proteins. There are also provided highly useful novel ligands for functional analysis of the GPR103 genes and proteins and for the compound evaluation. The nucleic acids or proteins having the sequences listed as SEQ ID NOS: 1 to 4 provide non-human primate or rat GPR103 genes and proteins and information based on the genes and proteins. The genes and proteins can be used for evaluation of compounds. The nucleic acids or proteins having the sequence listed as SEQ ID NO: 5 or 6 provide a GPR103 ligand.