Singar is identified as a novel molecule, whose expression is varied before and after the polarization of a nerve cell, and occurs in the tip of an elongating axon, called a growth cone, which is important for the formation or elongation of an axon. Singar is expressed specifically in the brain and the amount of Singar expression is largely increased in an individual during periods where the formation of axons is increased. It is observed that Singar is highly enriched in the growth cone at the tip of an axon. When the expression of Singar is inhibited in nerve cells in culture, the formation of multiple axons is induced. Thus, the inhibition of Singar can induce axon formation. Therefore, by inhibiting the expression or activity of Singar, it becomes possible to induce or promote the formation or elongation of an axon in a nerve cell.
