Intracerebral gene delivery of adeno‐associated vectors (AAV) has reached clinical testing for several LSD (Worgall et al, 2008; Leone et al, 2012; Tardieu et al, 2014) and a phase I/II clinical trial evaluating intracerebral AAV‐mediated delivery of the ARSA enzyme in late infantile MLD patients has started recently (ClinicalTrials.gov Identifier: NCT01801709). This evidence concerns the gene ARSA and metachromatic leukodystrophy.