The function of ENSG00000102934 (PLLP, plasmolipin) is as follows. Main component of the myelin sheath that plays an important role in myelin membrane biogenesis and myelination (PubMed:26002055). Plays an essential function in apical endocytosis. Regulates epithelial development through the regulation of apical endocytosis (By similarity). Part of the intracellular machinery that mediates basolateral-to-apical transport of ICAM-1, an essential adhesion receptor in epithelial cells, from the subapical compartment in hepatic epithelial cells (PubMed:34999972). {ECO:0000250|UniProtKB:A3KQ86, ECO:0000269|PubMed:26002055, ECO:0000269|PubMed:34999972}.