TSNARE1 (t-SNARE domain containing 1) is a schizophrenia-associated gene encoding syntaxin-like Qa SNARE proteins that regulate endosomal trafficking in cortical neurons 1. The protein localizes primarily to Rab7+ late endosomes and dendritic spines, where it acts as an inhibitory SNARE by competing with Stx12 for incorporation into endosomal SNARE complexes 1. This competition delays trafficking of dendritic cargo from early to late endosomal compartments, suggesting TSNARE1 negatively regulates endolysosomal trafficking 1. TSNARE1 was identified as a genome-wide significant schizophrenia/bipolar susceptibility locus (chr8.3, P = 1.28 × 10⁻⁹) 2 and implicated in suicidal thoughts and behaviors 3. Disease relevance extends beyond psychiatric conditions: altered plasma anti-TSNARE1 IgG antibody levels have been detected in schizophrenia patients, with sex-specific patterns in male patients 45, and heterozygous TSNARE1 duplication may associate with juvenile-onset leukodystrophy 6. Altered TSNARE1 expression affects neurodevelopment in zebrafish, indicating functional importance in brain development 7. These findings suggest dysfunction in vesicular trafficking and synaptic regulation may contribute to schizophrenia pathogenesis.