tokens: Infection of primary B-lymphocytes by Epstein-Barr virus ( EBV ) leads to growth transformation of these B-cells in vitro .
folded_tokens: infection of primary b-lymphocytes by epstein-barr virus ( ebv ) leads to growth transformation of these b-cells in vitro .
labels: O O B-cell_type I-cell_type O B-virus I-virus O B-virus O O O O O O O B-cell_type O O O