Plays a role in the regulatory network through which muscle cells coordinate their structural and functional states during growth, adaptation, and repair. High level of expression found in the heart and skeletal muscle, a very low expression in the lung and spleen and no expression found in the liver, kidney, fat and brain. Shows a differential expression level in the skeletal muscle, the expression in 65-day embryos being higher than other stages. Belongs to the SMPX family.