Lysobisphosphatidic acids (LBPAs), known also as bis-(monoacylglycerol)phosphates (BMPs) are specialized lipids reported to play a role in intracellular protein and lipid transport in healthy cells. Their accumulation was observed in pathologic liver tissue, and they also serve as antigens for auto-antibody generation in a human autoimmune condition termed antiphospholipid syndrome. Accumulation of LBPAs in intracellular, often multilamellar membranes is related to biomembrane polymorphism which may impact intracellular cholesterol transport. (S,S) Bisoleoyl-lysobisphosphatidic acid is the naturally occurring, biologically active isomer of LPBA.