FAM126A is a component of a complex required to localize phosphatidylinositol 4-kinase (PI4K) to the plasma membrane (PubMed:26571211). The complex acts as a regulator of phosphatidylinositol 4-phosphate (PtdIns(4)P) synthesis (PubMed:26571211). FAM126A plays a key role in oligodendrocytes formation, a cell type with expanded plasma membrane that requires generation of PtdIns(4)P (PubMed:26571211). Its role in oligodendrocytes formation probably explains its importance in myelination of the central and peripheral nervous system (PubMed:26571211, PubMed:16951682). FAM126A may also have a role in the beta-catenin/Lef signaling pathway (Probable) [taken from the Universal Protein Resource (UniProt) www.uniprot.org/uniprot/Q9BYI3].