LIF and ovarian cancer: One potential explanation for this phenomenon was provided by Rouas-Freiss et al. [19]; similar to our study, these authors demonstrated that ovarian cancer patients present with elevated serum levels of IL-10 and other immunomodulatory cytokines, such as leukemia inhibitory factor (LIF), granulocyte macrophage colony stimulating factor (GM-CSF) and IFN-gamma.