BFCN loss in AD and AUD (Lehericy et al., 1993; Vetreno et al., 2014) is accompanied by increases of Toll-like receptor 4 (TLR4) and the endogenous TLR ligand HMGB1 (Crews et al., 2013; Vetreno et al., 2013; Paudel et al., 2020). Here, TLR4 is linked to Alzheimer disease.