After detecting the mRNA and protein level of TLR3 in lung cancer cells (A549, NCI-H460, NCI-H1975 and SPC-A1) (Figures 3A, B), we investigated the effect of methylation on the expression of TLR3. We treated lung cancer cells with methyltransferase inhibitor 5-aza-dc and found that TLR3 mRNA was significantly increased in dose-dependent manner (Figure 3C). This evidence concerns the gene TLR3 and lung cancer.