GRN and Alzheimer disease: Certain GRN variants may also increase the risk for Alzheimer's disease (AD) (Brouwers et al, 2008; Rademakers et al, 2008; Viswanathan et al, 2009; Lee et al, 2011; Cruchaga et al, 2012; Sheng et al, 2014; Xu et al, 2017), yet associations could not be confirmed in some other studies (Fenoglio et al, 2009; Mateo et al, 2013).