SP1 and cancer: Their findings demonstrated that the mTERT promoter (containing additional Sp1 and c-Myc binding sites) induces a higher level of transgene expression than unmodified human TERT promoter in various TERT-positive cancer cells (up to 10-fold higher gene expression), showing that promoter activity can be improved in cancer through insertion of additional binding sites for oncogenic transcription factors upstream of the promoter.