For instance, hypomethylation of the promoter regions of genes encoding key pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6 has been observed to drive their increased expression in neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), Alzheimer’s (AD), and Parkinson’s disease (PD). Here, IL1B is linked to Parkinson disease.