APOE and Alzheimer disease: Additional one copy of APOE \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\varepsilon$$\end{document}ε4 gene would increase the risk of developing AD by 4-fold or more [8].