NEFL and Alzheimer disease: Notably, presenilin-1 (PSEN1) mutations cause most familial AD cases (Hurley et al., 2023), and emerging findings indicate that female PSEN1 carriers exhibit a higher level of plasma neurofilament light (NFL), a biomarker representing neurodegeneration, compared with male carriers (Vila-Castelar et al., 2023), suggesting that women may experience a higher rate of neurodegeneration than men.