In addition , the presence of an alternative promoter site , which exists within the intron downstream of the exon 1 , became evident .
in addition , the presence of an alternative promoter site , which exists within the intron downstream of the exon 1 , became evident .
O O O O O O O B-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region O O O O O B-DNA_domain_or_region O O O B-DNA_domain_or_region I-DNA_domain_or_region O O O O