In the excessive pruning observed in schizophrenia, DNA methylation (e.g., of genes encoding neurotrophic and inflammatory factors) and histone demethylation by the LSD1 (lysine-specific demethylase 1) affect microglial activation and the regulation of genes involved in synapse elimination (Park et al., 2022). The gene discussed is KDM1A; the disease is schizophrenia.