The Ile655Val SNP had no influence on the frequency of
HER2expression.However, the proline allele of the Ala1170ProSNPwas associated with a higher
frequency of HER2 overexpression (56% versus 43%, p Z 0.015). Where the germline genotype
was homozygous, the tumour genotype was identical in every case and for both SNPs. In
HER2-positive tumours, heterozygosity was maintained in only 15% and 18% of the Ile655Val
and Ala1170Pro SNPs, respectively.