The function of UNC79 (unc-79 subunit of NALCN channel complex, Ensembl gene identifier ENSG00000133958) is as follows. Auxilary subunit of the NALCN channelosome complex, which regulates the resting membrane potential by depolarizing sodium leak currents (PubMed:32494638, PubMed:35387979, PubMed:34929720). The NALCN channelosome complex is a voltage-gated ion channel responsible for the resting Na(+) permeability that controls neuronal excitability (PubMed:35387979, PubMed:34929720). The NALCN channelosome is constitutively active and conducts monovalent cations but is blocked by physiological concentrations of extracellular divalent cations (PubMed:32494638). Activated by neuropeptides substance P, neurotensin, and extracellular Ca(2+) that regulates neuronal excitability by controlling the sizes of NALCN-dependent sodium-leak current (By similarity). {ECO:0000250|UniProtKB:Q8N2C7, ECO:0000269|PubMed:32494638, ECO:0000269|PubMed:34929720, ECO:0000269|PubMed:35387979}.