Accordingly, we found that the C9orf72 expression was downregulated in SNpc of PD mice treated with A53T adenovirus (Figure 1F,G), which was accompanied by dysregulated autophagy (Figure 1F,H–J), such as the downregulation of LC3II/I expression and the upregulation of p62 and α‐synuclein expression, and the DA neurons were lost in SNpc (Figure S1C,D). Here, C9orf72 is linked to Parkinson disease.