SNX-2112 is a potent inhibitor of heat shock protein 90 (Hsp90) with a Kd value of 30 nM. In vitro, SNX-2112 induces down-regulation of the client proteins HER2 and Akt. It inhibits proliferation in a panel of cancer cell lines (IC50s = 10-50 nM). SNX-2112 (150 mg/kg) completely inhibits tumor growth in a BT474...