T cell expression of interleukin 3 ( IL-3 ) is directed by positive and negative cis-acting DNA elements clustered within 300 base pairs of the transcriptional start site .
t cell expression of interleukin 3 ( il-3 ) is directed by positive and negative cis-acting dna elements clustered within 300 base pairs of the transcriptional start site .
O O O O B-protein_molecule I-protein_molecule O B-protein_molecule O O O O O O O O O O O O O O O O O B-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region O