MBNL3 has been shown to inhibit muscle differentiation. MBNL3 belongs to a highly conserved family of tissue-specific alternative splicing regulators. This family is known to regulate terminal muscle differentiation through alternative splicing control and several groups have suggested that the family participates in the differentiation of photoreceptors, neurons, adipocytes and blood cell types. MBNL3 is expressed in myoblasts, muscle precursor cells, and during the early stages of myogenesis, but is detected at very low levels in terminally differentiated myotubes. MBNL proteins have been shown to sequester foci of expanded-repeat transcripts and are thought to therefore play a role in the molecular pathology of a group of neuromuscular diseases including the Myotonic Dystrophies.