Several genetic and epigenetic processes contribute to the silencing of tumour suppressor genes, including loss of genetic materials, mutation, promoter methylation, histone acetylation and post-transcriptional regulation by micro RNAs, etc. Loss of heterozygosity and deletion of chromosome 5p13, where DAB2 is located, is uncommon in NPC according to our previous studies [29-31]. This evidence concerns the gene DAB2 and neoplasm.