EPOR and neoplasm: Yasuda et al. (107) proposed the presence of a paracrine or autocrine EPO-EPOR loop and its contribution to tumorigenesis in female reproductive organs based on the mitogenic action of EPO as well as on the finding that injection of soluble EPOR (EPOR-S) or EPO-monoclonal antibody into blocks of tumor specimens was followed by apoptosis of tumor cells and endothelial cells.