Gastric cancer (GC) is the fifth most common cancer worldwide and the third leading cause of death from malignant tumours. 1 In China, the number of people who were newly diagnosed with GC was approximately 679,100 and almost 498,000 people died in 2015. 2 As most newly diagnosed with GC are identified at an advanced stage, five-year survival rate of patients is low. 3 The most common-used GC tumour markers, including carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 199, CA242 and CA724, are not sensitive or specific enough for GC screening and diagnosis, particularly for the early GC patients. 4,5 Considering that the five-year survival rate of patients with early GC can reach to 90%, 6 there is an urgent need to develop more effective and simple diagnostic biomarkers for detection of early GC.