EP300 and neoplasm: Under elevated hypoxic conditions, due to the uncontrolled cell growth and tumor expansion especially in the middle of the tumor mass, HIF-1α was shown to interact with the transcriptional co-factor p300/CBP, activating a wide range of genes, upregulating expression of the SLC2A1/GLUT1 receptor, and increasing glycolytic activity (46, 111–114).