Interestingly, by favoring fetal-type splicing events, the DM1 mutation favors the expression of long fetal MBNL1 isoforms in DM1 brains, as observed in DM1 muscles (Lin et al., 2006; Dhaenens et al., 2008). The gene discussed is MBNL1; the disease is myotonic dystrophy type 1.