A striking finding was that the interactions between smoking and polymorphism of CYP1A1 or GSTM1 gene increased significantly greater risk of NSCLC with hypermethylation of p16, DAPK or RARβ promoter, suggesting complex pathogenesis of NSCLC should be given top priority in future research. Here, DAPK1 is linked to non-small cell lung carcinoma.