In contrast, those AD pilot clinical trials assessing TZDs in subjects with early‐stage disease have found cognitive benefit in subjects comorbid for insulin resistance or those that are APOE4‐negative (Craft, 2012; Gold et al., 2010; Hanyu et al., 2009; Risner et al., 2006; Sato et al., 2011; Watson et al., 2005). This evidence concerns the gene APOE and Alzheimer disease.