Several previous studies have reported SORL1 × APOE interactions on the risk for AD (Cellini et al. 2009; Kimura et al. 2009) and on amyloid protein β (Aβ) concentrations in cerebrospinal fluid (CSF) in AD patients (Alexopoulos et al. 2011a, b). The gene discussed is SORL1; the disease is Alzheimer disease.