HDAC4 and rhabdomyosarcoma: Deletion of miR-1-2 in mice caused dysregulation of cardiogenesis [32]; miR-1 was found to promote apoptosis of cardiomyocytes; recently, miR-1 was also demonstrated to exert a strong pro-myogenic influence on poorly differentiated Rhabdomyosarcoma cells [33]; in skeletal myogenesis, miR-1 is known to be pro-myogenic through targeting histone deacetlylase 4 (HDAC4) [15].