TSPAN8 is a tetraspanin that functions as a structural organizer of tetraspanin-enriched microdomains (TEMs), which serve as signaling platforms on the plasma membrane 1. It orchestrates cell adhesion, migration, invasion, and signal transduction by assembling multimeric complexes with transmembrane and cytosolic proteins 2. TSPAN8 promotes mTORC2 activation through RICTOR and integrin interactions, enhancing cell migration 3, and regulates intestinal barrier function by modulating IFNGR1 endocytosis to limit inflammation 4. In cancer contexts, TSPAN8 displays oncogenic functions through multiple mechanisms: it promotes cancer stem cell stemness via sonic Hedgehog signaling activation 5, translocates to the nucleus to enhance STAT3-mediated transcription of cancer-promoting genes following EGFR-AKT signaling 6, and characterizes senescence-like cancer-associated fibroblasts that promote chemoresistance through SIRT6 degradation and metabolite secretion 7. TSPAN8+ chr12 remodeling fibroblasts exhibit poor prognostic significance across tissues 8. Metabolomic analyses associate TSPAN8 variants with type 2 diabetes and cancer 9. These findings establish TSPAN8 as an emerging therapeutic target, with monoclonal antibodies blocking its nuclear translocation showing antitumor effects 610.