Thus, the dysregulation of MBNL1 and CELF1 leads to isoform switches of several important genes related to skeletal muscle function, including CLCN1, BIN1, TNNT2, IR, and PKM, which directly cause DM1 disease phenotypes (Philips et al., 1998; Savkur et al., 2001; Charlet et al., 2002; Mankodi et al., 2002; Ho et al., 2004; Fugier et al., 2011). Here, CELF1 is linked to myotonic dystrophy type 1.