Although it was determined that the splicing of the IR (insulin receptor), cTnT (cardiac tropinin T), CLC-1 (chloride channel type 1) and PKM (pyruvate kinase) by CELF1 can promote insulin resistance, cardiac abnormalities and muscle wasting in DM1 disease [22-25], the identity of the CELF1 cancer associated pre-mRNA splicing targets remain elusive. Here, CLCN1 is linked to myotonic dystrophy type 1.