The function of ATP11B (ATPase phospholipid transporting 11B (putative), Ensembl gene identifier ENSG00000058063) is as follows. Catalytic component of a P4-ATPase flippase complex which catalyzes the hydrolysis of ATP coupled to the transport of aminophospholipids, phosphatidylserines (PS) and phosphatidylethanolamines (PE), from the outer to the inner leaflet of intracellular membranes (PubMed:30018401). May contribute to the maintenance of membrane lipid asymmetry in endosome compartment (PubMed:30018401). .