Finally, we show that pathogenic (CCUG)n DM2 repeat expansions activate the dsRNA-dependent protein kinase PKR, similar to previous reports in DM1 (Tian et al., 2000; Huichalaf et al., 2010; Wojciechowska et al., 2014). The gene discussed is EIF2AK2; the disease is myotonic dystrophy type 1.