TTR and proximal spinal muscular atrophy: Several ASOs have been approved for clinical use, e.g., targeting dystrophin (DMD) in Duchenne muscular dystrophy, transthyretin (TTR) in familial amyloid polyneuropathy (FAP) or survival of motor neuron 2 (SMN2) in spinal muscular atrophy (SMA), and dozens of ASOs are currently being investigated in clinical trials [17].