ESRRB and Duchenne muscular dystrophy: COUP-TF2, an orphan nuclear receptor, is expressed in various cell types in multiple tissues, where it has been implicated in the regulation of many physiological processes and pathological states including Duchenne muscular dystrophy (53), development and differentiation in multiple organs (54), liver fibrosis (55), endocardial cushion hypoplasia (56), and venous endothelial fate adoption in development (57).