INSM2 is a 566 amino acid nuclear protein. INSM2 is believed to act as a growth or tumor suppressor in certain neurons and in liver cells. INSM2 contains five zinc finger C2H2-type domains which bind nucleic acids. Zinc fingers are composed of 25-30 amino acid residues and have the ability to bind about five nucleotides. C2H2-type zinc fingers have two cysteines on one extremity of the domain, and two histidines on the other extremity. These four cysteines and histidines interact with one zinc atom, resulting in the finger-like conformation of the domain. It is believed that the C2H2-type zinc fingers require the binding of a zinc atom in order for the finger to bind DNA or RNA.