Reverse transcriptase inhibitors that target the L1 protein have been tested in a clinical trial for the neurodevelopmental disorder Aicardi-Goutieres syndrome [35, 36] and trials are currently underway in C9orf72 expansion positive individuals with ALS or frontotemporal dementia and in individuals with progressive supranuclear palsy. Here, C9orf72 is linked to Classical progressive supranuclear palsy.