Glycodelin A - a famous lipocalin and its role in breast cancer.

Lipocalins are a large protein family with only little sequence homology but highly conserved structural similarity. Many lipocalins play crucial roles in the generation of epithelial cancer, influencing pathways which regulate cell motility, cell differentiation and neovascularisation. Thereby they can be used as biomarkers of cancer, in most cases for a rather good prognosis. Glycodelin is a lipocalin existing in three isoforms which differ only by glycosylation, but which have different functions. In breast cancer, glycodelin A is known to contribute to a more differentiated cell morphology and is a biomarker for a favourable prognosis, but also plays a role in angiogenesis. Glycodelin A is a useful prognostic marker as it can be detected in serum samples, but is also a target for therapeutical interventions.