In AD, Hsp90 expression is downregulated, and after administration of Hsp90 inhibitor, Aβ-induced neurotoxicity could be prevented by increasing the level of Hsp70 and Hsp90 (Ansar et al., 2007; Gezen-Ak et al., 2013; Ou et al., 2014). The gene discussed is HSP90AA1; the disease is Alzheimer disease.