During stressed conditions, many cell types are known to upregulate APOE production in the brain, and recently, multiple studies have identified mechanisms by which APOE provides a detrimental effect, with the reduction of microglial or neuronal APOE favoring a protective effect towards several dementia pathologies (Koutsodendris et al., 2023; Liu et al., 2023; Yin et al., 2023). The gene discussed is APOE; the disease is dementia.