tokens: While virus derived from the clone containing the M47 mutation retained the ability to immortalize T lymphocytes , the M22 mutant lost the ability to immortalize infected cells .
folded_tokens: while virus derived from the clone containing the m47 mutation retained the ability to immortalize t lymphocytes , the m22 mutant lost the ability to immortalize infected cells .
labels: O O O O O O O O B-protein_molecule O O O O O O B-cell_type I-cell_type O O B-protein_molecule O O O O O O B-cell_type I-cell_type O