HSP90AA1 and Alzheimer disease: However, it is clear we are still in need of an effective treatment for all AD patients, and this review will look at how age-related chaperone imbalances in the human brain offer new emerging drug targets that may provide some hope for patients with this debilitating disease.23, 24 One such target that is gaining traction is the Hsp90–FKBP51 complex (Figure 1(a)–(c)).23