CD8A and cancer: In gastrointestinal tumours, ANO1 inhibits ferroptosis by activating phosphatidylinositol 3‐kinase (PI3K)/protein kinase B (PKB/AKT) signalling, promotes TGF‐β release, facilitates cancer progression, and promotes cancer‐associated fibroblast recruitment, which weakens CD8+ T‐cell‐mediated antitumor immune responses and generates resistance to immunotherapy.119