MUSK and proximal spinal muscular atrophy: Although MuSK agonist antibody #13 did not increase body weight of SMA mice, its beneficial effects in promoting synapse maintenance and preventing synapse disruption may be used as a complementary therapeutic intervention for SMA patients who may be poor responders to the three currently FDA-approved SMN-enhancing drugs, Spinraza, Zolgensma, and Evrysdi [40,41,42].