tokens: Reverse transcription-PCR analysis showed that all seven EBV -positive tumour tissues constitutively expressed EBV nuclear antigen ( EBNA ) 1 mRNA , but not EBNA2 mRNA .
folded_tokens: reverse transcription-pcr analysis showed that all seven ebv -positive tumour tissues constitutively expressed ebv nuclear antigen ( ebna ) 1 mrna , but not ebna2 mrna .
labels: B-other_name I-other_name I-other_name O O O O B-virus O O O O O B-virus O O O B-protein_family_or_group O O O O O O B-RNA_molecule I-RNA_molecule O