For example, cg12721804, which is hypermethylated in affected twins (Δβ = +.06, p = .001), is located in the last exon of DUSP4 (also known as mitogen-activated protein kinase phosphatase 2), which has been shown to be unregulated in the brains of individuals with depression who committed suicide (34). Here, DUSP4 is linked to major depressive disorder.