Given that ARVs are resistant to HSP90 inhibitors at a transcriptional level, can enter the nucleus independently of the HSP90 chaperone system and can be induced by AUY922 in primary tumors, we reasoned that persistent ARV-mediated signaling in prostate cancer cells could confer some level of resistance to HSP90 inhibition. The gene discussed is HSP90AA1; the disease is prostate cancer.