Similarly to ADARB2, several of the differentially methylated regions in blood overlapped or were closest to genes that are highly expressed in the brain or have been previously linked to neuronal functions or pathologies, such as neurogenesis, synaptic function, cognitive decline, intellectual disability, social interaction, schizophrenia, and Parkinson’s and Alzheimer’s diseases [24, 26–31]. The gene discussed is ADARB2; the disease is Parkinson disease.