TPP1 and cerebellar ataxia: In order to perform a global brain and cerebellar RNA-seq analysis in a mouse model of CLN2 at the disease end-stage (4-month-old) [28], we used the well-established model of cLINCL generated in Lobel’s laboratory that targets the Tpp1 mouse gene resulting in loss of detectable TPP1 activity and progressive neurological phenotypes including ataxia, motor deficiencies and blindness [29–33].