STX7 (syntaxin 7) is a Qa-SNARE protein that functions as a critical mediator of endo-lysosomal membrane trafficking and fusion events. Primary function: STX7 regulates endocytic trafficking from early endosomes through late endosomes to lysosomes 1 and participates in homotypic late endosome fusion 2 and autophagosome-lysosome fusion via the STX7-SNAP29-YKT6 SNARE complex 3. Mechanism: STX7 functions as a SNARE fusogen, forming distinct SNARE complexes with various VAMPs (VAMP2, VAMP3, VAMP7) and SNAP proteins to mediate membrane fusion 4. It is recruited to specific cellular compartments including the immunological synapse and invadopodia, where it directs targeted cargo delivery 54. Disease relevance: STX7 dysfunction associates with multiple pathologies—reduced STX7 expression correlates with increased seizure susceptibility in epilepsy, while STX7 overexpression decreases seizure activity by modulating inhibitory γ-aminobutyric acid release 1. STX7 variants show genetic association with unruptured intracranial aneurysms 6. Clinical significance: Intracellular pathogens including Salmonella hijack STX7 to evade lysosomal degradation 7, while IFITM3-STX7 interactions mediate antiviral immunity against influenza 2. STX7 promotes cancer cell invasion through invadopodia-dependent protease trafficking 4.