POU5F1 and facioscapulohumeral muscular dystrophy: For example, expression of DUX4, an activator of the zygotic genome in humans, in muscle cells leads to Facioscapulohumeral muscular dystrophy (FSHD), and OCT4 and Nanog are overexpressed in undifferentiated tumors and their expression is associated with poor clinical outcomes10,66–71.