GJA1 and Alzheimer disease: Interestingly, expression of both Cx43 and Cx30 was found to be upregulated in AD mice models (Mei et al., 2010) and brains from AD patients (Nagy et al., 1996), supporting the idea that Cxs may also play a role in neuronal dysfunction in AD (Orellana et al., 2009; Giaume et al., 2017).