Method for the in vitro diagnosis of endometriosis

In vitro diagnosis and monitoring of endometriosis, comprises detecting reduced expression of specific gene products, e.g. from the fibronectin gene In vitro diagnosis of endometriosis by determining the amount of gene product (I) from at least one specific gene (II) in a patient sample and comparing this with the amount of (I) in a control sample. A reduced level of (I) is indicative of endometriosis. (I) is a product of the fibronectin; insulin-like growth factor binding protein-2; transmembrane receptor PTK7; platelet-derived growth factor receptor alpha; collagen type XVIIIalpha1; subtilisin-like protein (PACE4); laminin M chain (merosin); elastin; collagen type IValpha2; p27 interferon alpha-inducible; reticulocalbin; aldehyde dehydrogenase 6; gravin; nodogen or phospholipase C epsi genes. Independent claims are also included for the following: (1) use of antibodies against proteins, or parts of them, encoded by (II) for diagnosis of endometriosis; and (2) a DNA chip that has bound to it at least one oligonucleotide that comprises a partial sequence of the specified genes, or their complements.