Update publication information. Gastroesophageal junction adenocarcinoma (GEJA) is a malignant tumor located at the junction of the esophagus and stomach, and its incidence is increasing yearly, while early screening for biological markers is limited. Tandem mass tag (TMT) combined with liquid chromatography-tandem mass spectrometry (LC–MS/MS) has been used to screen for differential proteins in various cancers. In the present study, we used TMT-LC–MS/MS to screen differential proteins in GEJA and precancerous lesions and then selected proteins that met the expectation for a trend clustering analysis combined with GO and KEGG analyses to functionally annotate differential proteins in GEJA. Then, parallel reaction monitoring (PRM) and immunohistochemistry (IHC) techniques were used to verify the accuracy of the proteomics data. In conclusion, our group used proteomics technology to screen differential proteins in the progression of GEJA and explored the expression trends of differential proteins in the occurrence of the carcinogenesis process and the functional areas involved, which provided detailed information for the elucidation of the progression process, pathogenesis, early screening and screening of candidate markers of GEJA.