HSP90AA1 and cancer: DNA G4 motifs have been found in promoter regions, usually within 1kb upstream of the transcription starting site (TSS), of many cancer-related genes, such as c-MYC, c-KIT, HIF, BCL-2, RET, k-RAS, h-RAS, HSP90, b-RAF, VEGF, hTERT [35,72] and MDM2 [36].