CC-90009 is less toxic than CC-885 and it has been shown to improve PTC readthrough in DMD (Duchenne muscular dystrophy), mucopolysaccharidosis type I-Hurler, late infantile neuronal ceroid lipofuscinosis, and JEB (junctional epidermolysis bullosis) patient-derived cells with nonsense mutations in the IDUA, TPP1, DMD, and COL17A1 genes. This evidence concerns the gene DMD and Duchenne muscular dystrophy.