Post-mortem neuropathological examination (e.g., with autoradiographical confirmation of Tau-PET binding in DM1 brain tissue) and studies with larger samples of DM1 participants are necessary to further evaluate whether other Tau PET tracers and/or fluid biomarkers could represent pathological biomarkers in DM1. The gene discussed is MAPT; the disease is myotonic dystrophy type 1.