GCG and type 2 diabetes mellitus: Based on previous studies, we hypothesize that there may be two primary mechanisms by which esophagectomy improves glucose levels in type 2 diabetes:(1) gastrointestinal rerouting caused by esophagectomy also significantly affected gastric emptying and altered gastrointestinal hormone (especially GLP-1) secretion, and (2) Changes of plasma ghrelin following esophagectomy lead to reduced eating behavior and weight loss, which affects glucose metabolism.