MMP9 and stomach disorder: In the current study, we evaluated the expression levels of PGC and a series of tumor markers such as monoclonal gastric cancer 7 antigen (MG7‐Ag), matrix metalloproteinase 9 (MMP9), NM23 nucleoside diphosphate kinase 1 (NM23), antigen identified by monoclonal antibody Ki‐67 (Ki‐67), and epithelial mesenchymal transition‐related protein E‐Cadherin in tissues from subjects with different gastric diseases.