MTPN (myotrophin), an ankyrin repeat protein, is stimulates protein synthesis and cardiomyocyte growth to initiate cardiac hypertrophy by activating the NF-kappaB signaling cascade. This protein plays a potential role in cerebellar morphogenesis and may function in differentiation of cerebellar neurons, particularly of granule cells. Elevated levels of MTPN are expressed in human dilated cardiomyopathic and ischemic hearts.