SMN1 and proximal spinal muscular atrophy: AAV9-SMN1 (named Zolgensma®) has been approved for intravenous injection for spinal muscular atrophy (SMA) patients while its inclusion/exclusion cut-off titer varied, including anti-AAV9 IgG < 1:50 or <1:400 or NAbs < 1:1 [8,9].