Within SCD and MCI/AD separately, plasma pTau181 was associated moderately with tau PET in SCD (range of β, 0.43–0.63; all P < 0.01) and associated weakly to moderately with tau PET in MCI/AD (range of β, 0.21–0.29; all P < 0.05) (Fig. 1A). The gene discussed is MAPT; the disease is Alzheimer disease.