There remain a number of unanswered questions regarding the endoscopic resection of large sessile lesions and expanding the ACE dataset in a new cohort of patients will allow these to be addressed. Enhancing the prediction of submucosal invasive cancer, advanced lesion classification, refinement of the assessment of deep injury, submucosal injectate constituents, the optimum electrosurgical resection methods, prevention and prophylaxis of bleeding, and subtype analyses of the different histological groups comprising AMN will be examined.