SMN1 and myopathy: The rationale for conducting our in vivo pharmacological studies in the Smn2B/− SMA mice was based on their longer lifespan [69], responsiveness to SMN-independent therapies [42, 47], established metabolic and myopathy defects [43, 47, 69–72], and later symptomatic onset [69] making them a clinically relevant model for starting treatment regimens >P5 time-points [42, 47].