The elevated mRNA levels of Dnmt3b were not significantly associated with hypermethylation of the six TSGs (p16, RARβ2, H-Cadherin, GSTP1, RIZ and FHIT), thereby suggesting that other factors might be involved in CpG island hypermethylation of TSG in a gene-specific basis in primary NSCLC [108]. This evidence concerns the gene DNMT3B and non-small cell lung carcinoma.