FRG1 and lung adenocarcinoma: However, global DNA hypomethylation has been recognized as a key epigenetic change in lung adenocarcinoma, inducing chromosomal instability and aberrant gene expression through alterations in the methylation levels in promoter CpG islands.21 As shown in Figure 2A, FRG1 variants detected in young and older lung adenocarcinoma patients were both located in the region of the FRG1‐like domain.