HIF-1α/1β heterodimer activates the HIF target gene and promotes HIF expression by combining the HIF-1α/1β heterodimer with p300/CBP and hypoxia response element (HRE), thus regulating various biological processes of tumor cells, including metabolic reprogramming, immunoregulation, angiogenesis, tumor cell invasion, and drug resistance (74, 75). The gene discussed is EP300; the disease is neoplasm.