Although originally identified in a screen designed to identify proteins that could bind to the cytoplasmic domain of the Fas receptor [61], DAXX is predominantly a nuclear protein which associates with both promyelocytic leukemia nuclear bodies (PML NBs) and ATRX-containing heterochromatic regions in S-phase of the cell cycle [36, 37]. Here, ATRX is linked to acute promyelocytic leukemia.