Provided is a method of inhibiting heterodimerization of HIF-2.alpha. to HIF1.beta. (ARNT) comprising binding certain small molecules to the HIF-2.alpha. PAS-B domain cavity but not to HIF1.alpha. and inhibiting HIF-2.alpha. heterodimerization to HIF1.beta. (ARNT) but not inhibiting HIF1.alpha. heterodimerization to HIF1.beta. (ARNT). Those certain small molecules are also referenced synonymously as HIF2-HDI and HIF2.alpha. heterodimerization inhibitors and also simply as certain small molecules.
 This invention was in part funded by grants from the National Institutes of Health (NIH) (P01 CA095471), CPRIT (RP-100846), CPRIT Grant the Cancer Center Support and Grant 5P30 CA 142543. Results shown in this disclosure were partially derived from work performed at Argonne National Laboratory, Structural Biology Center at the Advanced Photon Source. Argonne National Laboratory is operated by UChicago Argonne, LLC, for the U.S. Department of Energy, Office of Biological and Environmental Research under contract DE-ACO2-06CH11357. Results shown in this disclosure were also partially conducted in a facility constructed with support from the Research Facilities Improvement Program (Grant # C06 RR 15437-01) from the National Center for Research Resources, NIH. The government has certain rights in the invention.