To identify genes in the tumor that are specifically methylated at an early‐stage of LADC, we had previously performed a genome‐wide screening of aberrantly methylated CpG islands (CGIs) using paired tumorous and non‐tumorous tissues of early‐stage LADC, and identified TRIM58 as a novel candidate tumor‐suppressor gene for this disease.4 Through this screening, the glutamate decarboxylase 1 gene (GAD1) was found to be nearby hypermethylated CGIs in LADC. This evidence concerns the gene GAD1 and neoplasm.