Although Young et al. reported that DNMT inhibition caused cell cycle arrest and p21CIP/1WAF1 overexpression in normal human fibroblasts [66], Milutinovic et al. showed that inhibition of DNMT resulted in the rapid induction of p21CIP/1WAF1 without involvement of DNA demethylation in the p21CIP/1WAF1 promoter in the A549 human non-small cell lung cancer cell line [67]. Here, DNMT1 is linked to non-small cell lung carcinoma.