Based on this, the aim of this study is (1) to understand the evolutionary conservation of zebrafish Ace among vertebrates and its specific expression in the intestine; (2) to investigate the role of Ace in the development and progression of IBD; (3) to analyze the effects of ace deletion in zebrafish on intestinal inflammation; and (4) to confirm the role of Ace in intestinal inflammation using a dextran sodium sulfate (DSS)-induced IBD model. Here, ACE is linked to inflammatory bowel disease.