By subgroups, there was a weak positive correlation between myostatin and the MMT8 for ASyS (r = 0.35; p = 0.0009) and IBM (r = 0.32; p = 0.01) patients, and a moderate positive one for DM (r = 0.5; p < 0.0001) and IMNM patients (r = 0.43; p < 0.0001). Here, MSTN is linked to inclusion body myositis.