TF and Alzheimer disease: In a genome-wide association study (GWAS) study, Tf variant C2 positively correlates with AD risk with an OR of 1.21 (Bertram and Tanzi, 2008), which is supported by a number of independent studies (Van Landeghem et al., 1998; Schjeide et al., 2009; Kauwe et al., 2010) but was not confirmed in a recent large-scale GWAS study (Hollingworth et al., 2011).