ATRX and pancreatic neuroendocrine tumor: Prognosis as well as the genetic background of different ALT tumor types varies substantially, e.g., ALT gliomas and sarcomas frequently lose ATRX (reviewed in [49]), whereas pancreatic neuroendocrine tumors that use ALT have frequent DAXX mutations, but other ALT tumors do not associate with loss of ATRX/DAXX [75,76,77].