Consistent with our findings, plasma Aβ42/Aβ40, especially when combined with age and APOE ε4 status, have been shown to accurately stratify Aβ+ individuals (e.g. AUC, 0.80–0.85) in the AD continuum (Palmqvist et al., 2019b; Schindler et al., 2019). The gene discussed is APOE; the disease is Alzheimer disease.