The WMDs for subgroups divided by different male compositions were 0.48 (< 40% male, 95% CI − 0.18–1.14), 0.99 (40%–60% male, 95% CI 0.54–1.44) and 1.30 (> 60% male, 95% CI 0.39–2.21), respectively, indicating a strong effect of sex on plasma tau levels in AD patients (Fig. S5). The gene discussed is MAPT; the disease is Alzheimer disease.