Crucial in the assembly, expression, and functional modulation of the heterotrimeric complex of the sodium channel. The subunit beta-2 causes an increase in the plasma membrane surface area and in its folding into microvilli. Interacts with TNR may play a crucial role in clustering and regulation of activity of sodium channels at nodes of Ranvier. The voltage-sensitive sodium channel consists of an ion conducting pore forming alpha-subunit (SCN2A) regulated by one or more beta subunits (SCN1B, SCN2B, SCN3B and SCN4B). SCN1B and SCN3B are non-covalently associated with SCN2A. SCN2B and SCN4B are disulfide-linked to SCN2A (PubMed:26894959). Interacts with SCN10A and TNR. Brain specific. Detected in the earliest phase of neurogenesis in brain, and expression is greatly increased concomitant with axon extension and synaptogenesis. Belongs to the sodium channel auxiliary subunit SCN2B (TC 8.A.17) family.