Myogenic cell differentiation is regulated by the successive expression of MYOG, MEF2C, and MYF6.13 CARM1 has been identified as an important factor governing terminal muscle differentiation by binding to MEF2C to modulate target gene expression, such as creatine kinase.15 CARM1 also has the possibility to play a role in early muscle differentiation by activating Myog expression, although this was identified in the context of rhabdomyosarcoma-derived cells.16 Here, MEF2C is linked to rhabdomyosarcoma.