Oleinik et al. (2011) applied bisulfite conversion of DNA from 10 lung adenocarcinoma samples and conventional sequencing of upstream region, the first exon and the beginning of the first intron of ALDH1L1. Certain hypermethylation was observed in all three regions with no considerable preference. Although, the importance of the first exon of ALDH1L1 was emphasized in the experiments, since the exon was most extensively methylated in samples with a strongly downregulated ALDH1L1 gene, and also the addition of exon 1 to the reporter vector considerably enhanced luciferase expression. The gene discussed is ALDH1L1; the disease is lung adenocarcinoma.