In these tumours, p53 immunohistochemistry showed a diffuse or null (mutation) pattern (Tables 1 and 3), suggesting that the TP53- may reflect LOH and the resultant inactivation of wild-type TP53. Sequencing analyses of the mutation hot spots of TP53 have demonstrated that hemizygous mutations (i.e. mutation and LOH) were detected in the mucosal samples of 1 of the 3 intramucosal cancers and 1 submucosal cancer with a TP53- pattern, as well as the invasive parts of the 4 advanced cancers that were informative for TP53 mutation analysis. This evidence concerns the gene TP53 and cancer.