ARSB and mucopolysaccharidosis type 6: In clinical studies, AAV8.TBG.hARSB therapy with two copies of 101 bp of the AMBP enhancer and the −474/+3 region of the TBG promoter maintained 38–67% of normal arylsulfatase B (ARSB) activity in patients with mucopolysaccharidosis type VI (MPS VI) during 45 months of follow-up [219].