Nevertheless, an in vitro model demonstrated that pre-mRNAs containing large CCUG expansions are normally processed, that the expansions do not decrease CNBP expression at the mRNA or protein level, and that foci are enriched for the CCUG expansion, therefore different mechanisms could act at transcriptional level with respect to DM1 [70]. This evidence concerns the gene CNBP and myotonic dystrophy type 1.