Although APOE is the strongest predictor of late onset AD, the genetic SNP-based heritability explained by this locus is not high (0.05) (Escott-Price et al., 2017b) compared to genome-wide estimates (0.24–0.53) (Lee et al., 2013a; Ridge et al., 2016; Ridge et al., 2013). The gene discussed is APOE; the disease is Alzheimer disease.