SPON2 and gastric cancer: The EMT mediates tumour metastasis and relapse, and activation of the mitogen‐activated protein kinase (MAPK) pathway contributes to the development and progression of malignant tumours.26, 27, 28, 29 To identify the molecular mechanism through which SPON2 promotes metastasis of GC cells, we performed Western blotting to determine the levels of molecules that act downstream in the MAPK and EMT pathways.