There were 12 independent mutation events at a single mutation site , defining a small deletion hotspot .
there were 12 independent mutation events at a single mutation site , defining a small deletion hotspot .
O O O B-other_name I-other_name I-other_name O O B-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region O O O B-DNA_domain_or_region I-DNA_domain_or_region I-DNA_domain_or_region O