In terms of transcription factor inhibition, echinomycin was identified as a HIF1α and HIF1β/DNA binding inhibitor as evidenced using EMSA, luciferase activity and ChIP experiments on HIF-1 response elements (HRE) of the vascular endothelial growth factor promoter (VEGF, associated with tumor vascularization) [277]. This evidence concerns the gene HIF1A and neoplasm.