TFF2 and gastric cancer: The loss of chief cells results in various types of gastric diffuse mucosal injury, epithelial structural disorders and types of gastric metaplasia, classic precancerous lesions [12–17], including SPEM (with predominant expression of Tff2 and Muc6) and IM (with the expression of CDX2, Muc2, and Tff3) [32], which ultimately develop into GC.