Previous studies have proven that NAV2 plays a key role in the development of the mammalian nervous system, resulting in abnormal nerve fiber density and in causing developmental defects of nerves in early embryos following NAV2 deletion.254 NAV2 is also an indispensable protein molecule in the outward growth of human neuroblastoma cells induced by all-trans retinoic acid.255. The gene discussed is NAV2; the disease is neuroblastoma.