Insulin receptor substrate P53 (IRS P53) has been identified as a brain-specific angiogenesis inhibitor (BAI1)-binding protein. This interaction at the cytoplasmic membrane is crucial to the function of IRS P53, which is involved in neuronal growth-cone guidance. This protein functions as an insulin receptor tyrosine kinase substrate and suggests a role for insulin in the central nervous system. IRS P53 has also been identified as interacting with the dentatorubral-pallidoluysian atrophy gene, which is associated with an autosomal dominant neurodegenerative disease. It also associates with a downstream effector of Rho small G proteins, which is associated with the formation of stress fibers and cytokinesis.