Of note, p53R270H but not p53R172H also acted in a dominant-negative manner in promoting tumorigenesis when the other allele was WT for p53. Moreover, the expression of mutant p53 was found to contribute to tumour heterogeneity by promoting the development of sino-nasal adenocarcinomas, which was not observed in tumours with a p53-deficient state [89]. This evidence concerns the gene TP53 and neoplasm.