(A) Animal model studies. Mixed effects, indicating that different results have been reported when the intervention was applied in different experimental settings (e.g. in acute or chronic stages of disease, in prophylactic versus therapeutic protocols, or when using different inhibitors). See the main text for details. (B) Human trials. AD, Alzheimer’s disease; ALS, Amyotrophic lateral sclerosis; CADASIL, Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy; CMT1X, Charcot–Marie–Tooth disease type 1X; CRL, CSF-1R-related leukoencephalopathy; GCL, globoid cell leukodystrophy; HD, Huntington’s disease; MS, multiple sclerosis; PD, Parkinson’s disease; TBI, traumatic brain injury.