The PuF site on the silent normal c-myc allele was unoccupied .
the puf site on the silent normal c-myc allele was unoccupied .
O B-DNA_domain_or_region I-DNA_domain_or_region O O B-DNA_domain_or_region I-DNA_domain_or_region B-DNA_domain_or_region I-DNA_domain_or_region O O O