CSF1 and ovarian cancer: Extracellular signals that induce VEGF-A through this proximal region include, among others, growth factors such as EGF, insulin and PDGF in fibroblasts[18], prostaglandin E2 in human muscle cells[27], M-CSF in monocytes[28] and lysophosphatidic acid (LPA) in ovarian cancer cells[29].