Our research aimed to validate novel LUAD-specific and GAC-specific methylation biomarkers that successfully differentiate LUAD and GAC from cholangiocarcinoma (CCA), colorectal carcinoma (CRC), hepatocellular carcinoma (HCC), pancreatic adenocarcinoma (PDAC) and the normal adjacent tissues (NATs). Here, GLS is linked to colorectal carcinoma.