MBNL1 and myotonic dystrophy type 1: Previously, it has been shown that MBNL1 directly regulates the excision of the miR-1 duplex from its pre-miRNA; however, our data also indicated that miR-1 and miR-206 change at the transcript level, with clear pri-miRNA level alterations in two MBNL1-deficient mouse models (Figure 1E and F) and in DM1 patients (Figure 5).