DUX4 is a gene that plays a crucial role in muscle development and function. It is primarily known for its involvement in a genetic condition called Facioscapulohumeral muscular dystrophy (FSHD), which leads to progressive muscle weakness and wasting. In individuals with FSHD, abnormal expression of DUX4 causes muscle cells to become damaged and die. Research on DUX4 aims to understand its mechanisms and develop potential therapies to treat or manage FSHD and related muscle disorders.