In the same line, epigenetic modifications, particularly DNA methylation, critically regulate gene transcriptional activity, i.e., evidence shows that NSCLC cell lines harboring an unmethylated EGFR promoter exhibit increased sensitivity to gefitinib relative to those with promoter hypermethylation, implicating EGFR promoter methylation as a potential mechanism underlying off-target AR [22] (Figure 2). The gene discussed is EGFR; the disease is non-small cell lung carcinoma.