These reductions also affect their corresponding mRNAs both in animal models of stress (Sun et al., 2012) and in humans subjects with depression (Nagy et al., 2016) and have been convincingly attributed to epigenetic marker alterations such as methylation of histone 3 at Cx43 and Cx30 genes in the prefrontal cortex using chromatin immunoprecipitation (Nagy et al., 2016). Here, GJB6 is linked to major depressive disorder.