In a recent study of DNA methylation at sites within γ‐aminobutyric acid‐related genes in the post‐mortem hippocampus of individuals with schizophrenia or BD, the majority of significant DMPs and DMRs were found to map to MSX1. 52MSX1 encodes a transcription factor that is involved in regulating central nervous system development, including the differentiation of midbrain dopaminergic neurons.64, 65 Hannon et al.24 identified a significant positive correlation between methylation in the blood and the STG for three of the four probes that form this DMR. The gene discussed is MSX1; the disease is Behcet disease.