TP53 and neoplasm: To test the hypothesis that the BRCA2 heterozygous genotype provides protection in comparison with either of the homozygous genotypes at the -26 position in the 5' UTR, allelic imbalance for the selected informative markers in chromosomes 16 and 17 was studied along with mutation in the p53 gene (mutation details provided in Additional File 1) in a panel of normal and tumor tissues already characterized for the polymorphism.