DAXX and alpha thalassemia spectrum: For example, H3.3 can be deposited into chromatin at highly transcribed regions by the histone regulator A (HIRA) complex [57,58], but can also be found at telomeres and repetitive heterochromatic regions where it is deposited by a complex comprising alpha thalassemia, mental retardation syndrome X-linked (ATRX), and death domain associated protein (DAXX) [59,60,61].