In heart samples from patients with DM1 cardiomyopathy or DM1 non‐diabetic arrhythmia, RBFOX2 upregulation is coupled with the selective upregulation of the RBFOX2‐40 isoform (a type of RBFOX2‐DN).26 Here, RBFOX2 is linked to myotonic dystrophy type 1.