Abstract: The present invention relates to the provision of a nucleic acid molecule encoding a Caviidae allergen comprising a polynucleotide selected from the group consisting of (a) a polynucleotide sequence as shown in SEQ ID NO 1 (Cav p 3), SEQ ID NO 5 (Cav p 2), SEQ ID NO 3 (Cav p 6) or SEQ ID NO 19 (Cavia porcellus allergen 1 a) or a fragment thereof, (b) a polynucleotide sequence encoding a polypeptide as shown in SEQ ID NO 2 (Cav p 3), SEQ ID NO 6 (Cav p 2), SEQ ID NO 4 (Cav p 6) or SEQ ID NO 20 (Cavia porcellus allergen 1 a) or a fragment thereof (c) a polynucleotide sequence which has at least 80% identity to the polynucleotides as defined in (a) or (b) encoding a Caviidae allergen or a fragment thereof, (d) a polynucleotide sequence encoding a polypeptide which has at least 85% identity to the polypeptide as shown in SEQ ID NO 2 (Cav p 3), SEQ ID NO 6 (Cav p 2), SEQ ID NO 4 (Cav p 6) or SEQ ID NO 20 (Cavia porcellus allergen 1a) or a fragment thereof, (e) a polynucleotide sequence which hybridizes to the poly