Effects of 17-AAG on client protein levels in primary AML isolates. Aliquots containing 1.5 × 10⁶ to 2 × 10⁶ AML cells were incubated for 24 hours with diluent (lane 1), 300 or 1000 nM cytarabine (lanes 2 and 3), or 300 or 1000 nM 17-AAG (lanes 4 and 5). Whole cell lysates containing 50 μg protein were then subjected to immunoblotting with reagents that detect the indicated polypeptides. Actin, which is not an Hsp90 client, and Hsp90, which does not change after 17-AAG treatment, served as loading controls. Samples in panels A-C came from 3 different AML patients.