Fig. 3
![Fig. 3](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13195-019-0566-0/MediaObjects/13195_2019_566_Fig3_HTML.png)
a Plasma Aβ1–42 levels in amyloid PET− and PET+ APOE ε4 carriers and APOE ε4 non-carriers. b Plasma Aβ1–42 levels in amyloid PET− and PET+ APOE ε4 carriers and non-carriers. APOE ε4 non-carriers are divided into APOE ε2 carriers and non-carriers. The dashed and dotted lines are the plasma Aβ1–42 cut-off values, 18.68 pg/ml and 15.58 pg/ml, for differentiating PET− from PET+ in APOE ε4 carriers and non-carriers, respectively. Abbreviations: Aβ, Amyloid β; PET+, amyloid positron emission tomography positivity; PET−, amyloid positron emission tomography negativity