Scn2b encodes one type of beta subunit found in voltage-gated sodium channels. These channels, composed of one alpha and one or two different beta subunits, mediate changes in cell permeability to sodium ions that are essential for the generation of action potentials. Scn2b protein, comprised of an extracellular N-terminus with an immunoglobulin-like fold and a single transmembrane domain, has been shown in brain tissues to be covalently linked through disulfide bonds to the alpha subunit. Scn2b is considered an auxiliary subunit that modulates cell-surface expression and gating, though its function in heart myocytes may be limited to cell adhesion. Scnb2 null mice display increased susceptibility to seizures. Expression of Scn2b has been shown to be suppressed with exposure to pneumococcal acute otitis media.