In the current study, we revealed that the inhibitory core of the myostatin prodomain (42CTWRQNTKSSRIEAIKIQILSKLRLETAP70) resides near its N-terminus by expressing various prodomain regions as Fc fusion proteins in both HEK293 embryonic kidney cells, or A204 rhabdomyosarcoma cell. Here, MSTN is linked to rhabdomyosarcoma.