TTYH1 (tweety family member 1) functions as a calcium-independent, volume-regulated anion channel (VRAC) with multiple cellular roles beyond ion transport 1. The protein contains five transmembrane domains and localizes to plasma membranes, where it mediates chloride transport in response to cell swelling 12. TTYH1 exhibits LRRC8A-independent VRAC activity and is critical for maintaining volume-regulated chloride currents in various cancer cell lines 1. Beyond ion channel function, TTYH1 plays important roles in cell migration, invasion, and membrane remodeling. In osteosarcoma cells, TTYH1 promotes cell migration and invasion through regulation of epithelial-mesenchymal transition factors and matrix metalloproteinases 3. In gliomas, TTYH1 drives brain colonization by regulating tumor microtube formation, with cells expressing TTYH1 showing enhanced invasive capacity 4. Recent evidence reveals an endolysosomal function where TTYH1 facilitates autophagic flux and lipid droplet degradation in astrocytes by mediating ceramide 1-phosphate clearance 5. Additionally, TTYH1 demonstrates membrane-bending activity and can induce extracellular vesicle formation, similar to prominin-1 6. The protein is highly expressed in neural tissues and various cancers, suggesting both developmental and pathological significance 24.