The function of SCNN1A (sodium channel epithelial 1 subunit alpha, ENSG00000111319) is as follows. This is one of the three pore-forming subunits of the heterotrimeric epithelial sodium channel (ENaC), a critical regulator of sodium balance and fluid homeostasis (PubMed:30251954, PubMed:32729833, PubMed:8023962, PubMed:8278374, PubMed:9792722). ENaC operates in epithelial tissues, where it mediates the electrodiffusion of sodium ions from extracellular fluid through the apical membrane of cells, with water following osmotically (PubMed:24124190, PubMed:28710092, PubMed:8278374). It plays a key role in maintaining sodium homeostasis through electrogenic sodium reabsorption in the kidneys (PubMed:12107247). Additionally, ENaC is essential for airway surface liquid homeostasis, which is crucial for proper mucus clearance (PubMed:24124190, PubMed:28710092). {ECO:0000269|PubMed:12107247, ECO:0000269|PubMed:24124190, ECO:0000269|PubMed:28710092, ECO:0000269|PubMed:30251954, ECO:0000269|PubMed:32729833, ECO:0000269|PubMed:8023962, ECO:0000269|PubMed:8278374, ECO:0000269|PubMed:9792722}. [Isoform 4]: Not functional. .