The HEK-293T HRE-NanoFIRE line represents a sensitive reporter system specifically for HIF-1, given that HEK-293T cells do not express HIF-2α [9] (Figure 2A,B) and would thus be ideal for small molecule drug screening to identify novel compounds which specifically modulate HIF-1 activity, in particular those that directly inhibit HIF-1 which would have broad therapeutic potential in cancer. The gene discussed is EPAS1; the disease is cancer.