May have an involvement in muscle development or hypertrophy. Isoform 2 binds to RBP-J and plays a negative regulatory role in the RBP-J-mediated transcription in mammalian systems. Additional isoforms seem to exist. Isoform 1 seems to be most abundant in each tissue and isoform 2 much less abundant. Isoform 1 is highly expressed in skeletal muscle and lung, and to a lesser extent in heart, brain and kidney. Isoform 2 was found in brain, lung kidney and genital organs.