May affect the movement of lipids in the cytoplasm or allow the binding of lipids to organelles. Widely expressed; the highest levels are in prostate, lung and placenta; also detected in kidney, bone marrow, spleen, thymus, spinal cord, adrenal gland, salivary gland, trachea and mammary gland; levels are low in brain, heart, fetal liver, pancreas and testis. In vitro, is responsive to TNF. Belongs to the apolipoprotein L family.