NXN and Alzheimer disease: Given that NRX-based synaptic organizing complexes are essential for regulating synapse organization, synaptic transmission and synaptic plasticity under physiological conditions and are also required for normal cognitive functions (Südhof, 2017; Kasem et al., 2018), the Aβ-induced dysregulation/dysfunction of NRXs would be a key mechanism underlying synaptic pathology and cognitive decline in AD.