Despite this, we previously found that AAV9-mediated gene transfer of MCOLN1/TRPML1 directed to neurons was sufficient to fully restore neurologic function in Mcoln1−/− mice without reducing microgliosis and astrocytosis, therefore dismissing the primary role of these cells in driving MLIV pathogenesis (De Rosa et al., 2021). This evidence concerns the gene MCOLN1 and mucolipidosis type IV.