Functions as a negative regulator of myocyte differentiation. May interact with both sarcoplasmic structural proteins and nuclear proteins to regulate gene expression during muscle development and in response to muscle stress. {ECO:0000269|PubMed:21737686, ECO:0000269|PubMed:22016770}. This is the function of ANKRD2 (ankyrin repeat domain 2, ENSG00000165887).