ISL LIM Homeobox Protein 1 (ISL1)

ISL1encodes a transcription factor containing two N-terminal LIM domains and one C-terminal homeodomain. The encoded protein plays an important role in the embryogenesis of pancreatic islets of Langerhans. In mouse embryos, a deficiency of this gene fail to undergo neural tube motor neuron differentiation.

ISL1 is a marker for cardiac progenitors of the secondary heart field (SHF) which includes the right ventricle and the outflow tract. It also has a biological function as shown in Isl1 knockout mice which have a severely deformed heart. More recently it has been defined as a marker for a cardiac progenitor cell lineage that is capable of differentiating into all 3 major cell types of the heart: Cardiomyocytes, smooth muscle and endothelial cell lineages.