Mechanistically, asparagine endopeptidase (AEP) upregulates Twist to promote peritoneal metastasis in gastric cancer 39; EG-1 upregulates eIF4E-mediated MMP-9 and Twist to facilitate gastric cancer metastasis 40; TrkB promotes EMT and Twist-enhanced peritoneal metastasis and apoptosis resistance in ovarian cancer 41. Here, MMP9 is linked to gastric cancer.