For example, patients with severe COVID-19 have elevated plasma GFAP (Cooper et al., 2020; Sahin et al., 2022), which was associated with subsequent mild cognitive impairment (Bark et al., 2023), and blood GFAP is also becoming recognized as a biomarker for Alzheimer’s disease (Ally et al., 2023; Chatterjee et al., 2021; Pereira et al., 2021; Sánchez-Juan et al., 2024). Here, GFAP is linked to early-onset autosomal dominant Alzheimer disease.