LCN2 and Alzheimer disease: Lcn2 is secreted from astrocytes under AD-mimicking conditions (Dekens et al., 2020, Staurenghi et al., 2021) and acts as an autocrine mediator of reactive astrocyte responses (Lee et al., 2009) that causes synaptic toxicity, neuronal death and cognitive deficits (Kim et al., 2017, Lee et al., 2012a, Staurenghi et al., 2021).