For example, these genes included CABLES1, whose expression is necessary for neurite outgrowth and which is a substrate of c-Abl tyrosine kinase, an important kinase in neurulation [50, 51] and STX1A, a nervous-system specific protein that contributes to neurite outgrowth and has been associated with both autism and attention deficit/hyperactivity disorder [52, 53]. The gene discussed is STX1A; the disease is attention deficit-hyperactivity disorder.