Some patients with IH present a heterozygous germline missense mutation in the extracellular region of the VEGFR2 gene which encodes vascular endothelial growth factor receptor 2 (VEGFR2), while other patients are presented a mutation in the ANTXR1 (Anthrax toxin receptor 1, TEM8) gene (OMIM 606410), which affects the transmembrane domain of TEM8/ANTXR1 protein [67]. The gene discussed is ANTXR1; the disease is isolated hemihyperplasia.