SLC6A4 and Behcet disease: In other studies, there are reports on the loss of the lateralized expression of DTNBP1 due to its altered promoter DNA methylation in SCZ and BD patients compared to the control subjects [99], in addition to the loss of the lateralized expression of (i) MB-COMT (membrane-bound COMT), (ii) HTR2A (serotonin type-2 receptor, reduced in the left brain of SCZ and right brain of BD patients), and (iii) SLC6A4 (5-HTT, serotonin transporter) in the post-mortem brains of patients with SCZ and BD, all associated with corresponding DNA methylation changes versus the control subjects [131,132,133].