Pfister et al. (2018) have performed an experiment in HD transgenic sheep model that expresses the full-length human HTT with 73 CAG repeats. Treatment of these animals with AAV9-expressing an artificial miRNA targeting exon 48 of the human HTT transcript has led to a reduction of human mHTT transcript and protein in the striatum without any significant neuron loss. This study has revealed the safety and efficiency of silencing human mHTT protein using an AAV-mediated transfer of an artificial miRNA (Pfister et al., 2018). This evidence concerns the gene HTT and Huntington disease.