tokens: EBNA-5 is one of the Epstein-Barr virus ( EBV ) -encoded nuclear proteins required for immortalization of human B lymphocytes .
folded_tokens: ebna-5 is one of the epstein-barr virus ( ebv ) -encoded nuclear proteins required for immortalization of human b lymphocytes .
labels: B-protein_molecule O O O O B-virus I-virus O B-virus O O O O O O O O B-cell_type I-cell_type I-cell_type O