Transgenic mice that overexpress CUG-BP1 in muscle and heart reproduce missplicing alterations typical of DM1, which has confirmed the involvement of this protein in the pathogenesis of the disease as well as the antagonism between MBNL1 and CUG-BP1 in alternative splicing regulation ([70] and below). The gene discussed is MBNL1; the disease is myotonic dystrophy type 1.