For a clinical trial aimed at reducing the risk of conversion to AD by 30% over four years (Fig. 3; Supplementary Table 8), a significant reduction in required sample size was observed when enriching for plasma P-tau217 (SSΔ = 48%, CI [38,56], P < 0.001) and plasma Aβ42/Aβ40 (SSΔ = 48%, CI [35,60], P = 0.001), while plasma NfL did not significantly enrich such a clinical trial (SSΔ = 24%, CI [−10, 45], P = 0.20). Here, NEFL is linked to Alzheimer disease.