Expression of CXCR2 by the ovarian cancer cells themselves has also been demonstrated, and it has been shown that it can promote angiogenesis by increasing levels of vascular endothelial growth factor (VEGF) and decreasing levels of thrombospondin-1 (TSP-1) via a mitogen-activated protein kinase (MAPK) and a signal transducer and activator of transcription 3 (STAT3) dependent mechanisms [45]. This evidence concerns the gene THBS1 and ovarian cancer.