TS enhancer region , 3R G > C single nucleotide polymorphism ( SNP ) , and TS 1494del6 polymorphisms were assessed in both fresh-frozen normal mucosa and tumor .
B-GeneOrGeneProduct O O O O B-SequenceVariant I-SequenceVariant I-SequenceVariant O O O O O O O O B-GeneOrGeneProduct B-SequenceVariant O O O O O O O O O B-DiseaseOrPhenotypicFeature O