Twenty years ago, Nagy and colleagues have firstly demonstrated that astrocyte Cx43 protein levels are increased in the brain tissue of AD patients, especially around the Aβ plaques (Nagy et al., 1995), which has been repeatedly confirmed (Kajiwara et al., 2018), and is also found in the APP/PS1 mouse model (Mei et al., 2010; Yi et al., 2016). Here, APP is linked to Alzheimer disease.