Apolipoprotein D (ApoD) is an extracellular glycoprotein of the lipocalin protein family, involved in different functions such as immune response, cell proliferation regulation, chemoreception, retinoid metabolism, axon growth, and proteolysis regulation. This lipocalin is expressed predominantly in the nervous system (NS), both prenatally (vascular pericytes) and postnatally (glia and neurons) and in adulthood. It is also expressed in other tissues and is carried by high-density lipoprotein

more »

... L) in plasma, so it could interfere in cholesterol and other lipids regulation. ApoD increases considerably in systemic apocrine gland tumors and also in some primary brain tumors. Although the specific biological role of ApoD is unknown, the presence of ApoD in tumors appears to be a prognostic factor in their evolution. Regarding the NS, increased ApoD expression observed in many neurodegenerative diseases could be used to make an early diagnosis thereof.