MAPK3 and gastric adenocarcinoma: Western blotting, qRT-PCR, immunofluorescence, co-immunoprecipitation (Co-IP), wound healing, MTT, and Transwell invasion analyses, and nude mouse orthotopic tumor models were applied to investigate the function and mechanism of the ER-α36/SGK1/Erk1/2 axis.<h4>Results</h4>ER-α36 was positively expressed in 62.3% of gastric adenocarcinoma tissues and was associated with poor differentiation and prognosis.