Moreover, the biodistribution of ICV‐transplanted HSPCs in the CLN1 disease mouse brain could be inefficient or uneven in some regions, which could explain the striking accumulation of AF storage in the cerebellum and the thalamus (consistent with the lower hPPT1 immunostaining observed in these regions, as compared with the other gene therapy groups). Here, PPT1 is linked to glycogen storage disease VI.