Consistent with data by Soria and colleagues, Maeda and his team explored a possible correlation between hypermethylation of CpGs located at the PTEN gene promoter region and resistance to gefitinib or erlotinib in the two lung cancer cell sublines GEF1-1 and GEF2-1 (obtained from cell line harboring the EGFR mutation p.E746_A750del). This evidence concerns the gene EGFR and lung cancer.