IL11 is a multifunctional cytokine first isolated in 199 from bone marrow-derived stromal cells. It is a key regulator of multiple events in hematopoiesis, most notably the stimulation of megakaryocyte maturation. IL11 is also known under the names adipogenesis inhibitory factor (AGIF) and oprelvekin. IL11 can improve platelet recovery after chemotherapy-induced thrombocytopenia, induce acute-phase proteins, modulate antigen-antibody responses, participate in the regulation of bone cell proliferation and differentiation, and could be used as a therapeutic for osteoporosis. IL11 stimulates the growth of certain lymphocytes and, in the murine model, stimulates an increase in the cortical thickness and strength of long bones. As a signaling molecule, IL11 has a variety of functions associated with its receptor interleukin 11 receptor alpha; such functions include placentation and to some extent of decidualization.

> 95 % as determined by SDS-PAGE.