Several mouse models of DM1 have been developed and studied for research on DM1, whereas the most common of which is the HSALR DM1 mouse expressing 250 CTG repeats in a human skeletal actin (ACTA1) transgene8, where is different from the genuine mutation locus in DM1 patients. The gene discussed is ACTA1; the disease is myotonic dystrophy type 1.