GPT and central nervous system cancer: Interestingly, the high-ALT “At” quadrant and the high TEL quadrant “aT” associate with the downregulation of ATRX and the upregulation of TERT, respectively (see gene locations marked by crosses in the At and aT portraits), which are also known to switch-on ALT and TEL TM in other cancer types, such as gliomas [78].