PRNP and Alzheimer disease: Ondrejcak et al. (2018) reported that intracerebral application of soluble recombinant tau or soluble tau extracted from AD brain inhibited LTP in mice, and anti-PrP antibodies antagonized the effect. On the basis of this, the authors indicate PrPc as essential for tau-mediated neuronal disruption of synaptic plasticity in vivo. Along this line, Boutajangout et al. (2021) showed that passive immunization with a new anti-PrP antibody significantly reduced tau pathology, resulting in improved cognitive function in a hTau/PS1 transgenic mouse model of AD.