In patients with endometriosis, ICOS ligand, Endothelial growth factor, E-selectin, Receptor tyrosine-protein kinase erbB-2, Interleukin-6 receptor alpha, Vascular endothelial growth factor receptor 2, Fms-related tyrosine kinase 3 ligand, C-X-C motif chemokine 10, Epididymal secretory protein E4 and Folate receptor-alpha were decreased, while Interleukin-6 and Interleukin-8 were increased compared to controls. This evidence concerns the gene KDR and endometriosis.