SNARE promoting movement of transport vesicles to target membranes. Targets endosomes to the trans-Golgi network, and may therefore function in retrograde trafficking. Together with SNARE STX12, promotes movement of vesicles from endosomes to the cell membrane, and may therefore function in the endocytic recycling pathway. . This is the function of ENSG00000135823 (STX6, syntaxin 6).