We describe a method of identifying a molecule suitable for the treatment, prophylaxis or alleviation of a GPR86 associated disease, in particular inflammatory disease or pain, the method comprising determining whether a candidate molecule is an agonist or antagonist of GPR86 polypeptide, in which the GPR86 polypeptide comprises the amino acid sequence shown in SEQ ID NO: 3 or SEQ ID NO: 5 or SEQ ID NO: 7, a fragment thereof or a sequence which is at least 90% identical thereto.