GJA1 and major depressive disorder: Emerging evidence has suggested that dysfunction of Cx43 is predisposed to depression (Sun et al., 2012; Xia et al., 2018), and the inflammatory reaction relies, at least in part, on intercellular communication mediated by Cx43 proteins and their channels (Willebrords et al., 2016; Medina-Ceja et al., 2019; Li et al., 2020a).