Provided herein is an isolated tumour necrosis factor receptor (TNFR) polypeptide capable of binding to TNF, or a TNF-binding fragment thereof, wherein the polypeptide comprises an amino acid sequence of SEQ ID NO:1, or an amino acid sequence that has at least 60% identity thereto and wherein the polypeptide or TNF-binding fragment comprises an N-terminal VPAQV motif, with the proviso that the polypeptide is not mouse TNFR p80 isoform. Also provided is a fusion protein comprising said polypeptide, or a TNF-binding fragment thereof, linked to a fusion partner, such as the CH2 and CH3 domains of an immunoglobulin heavy chain constant region. The polypeptides and fusion proteins disclosed herein may be used for diagnostic purposes and in the treatment or prevention of conditions mediated by TNF, particularly in non-human animals such as feline and equine.
