High expression of MSTN can lead to muscle atrophy.[11,37] In an animal experiment, acupuncture combined with low-frequency electrical stimulation downregulated the expression of MSTN and helped to alleviate muscle atrophy in mice.[14] However, the in vivo expression level of MSTN in SIM patients and its relationship with SIM are not clear. The gene discussed is MSTN; the disease is Atrophy.