EPAS1 and lung cancer: Herein, HIF-1α and HIF-2α protein levels were analyzed in EPLC-272H and H1339 lung cancer cells under normoxic ([O2] = 21%) and hypoxic ([O2] = 0.66%) conditions, in the presence and absence of two structurally distinct Hsp90 inhibitors, 17-AAG and NVP-AUY922.