In addition, glutathione S-transferase (GST) pull-down assay demonstrated that HIF-2α physically interacts with ETS1 [26], and immunoprecipitation analysis showed that HIF-2α forms a complex with Elk1 in MCF7 (breast cancer) and 786-O (renal cell carcinoma) cells [27]. The gene discussed is ELK1; the disease is renal cell carcinoma.