Interleukin-11 (IL-11) is encoded by the IL11 gene and is a member of IL-6 superfamily, distinguished based on their use of the common co-receptor gp130. It is a multifunctional cytokine first isolated from bone marrow-derived stromal cells. IL-11 receptor activation requires formation of a complex of two IL-11 molecules with two molecules of the ligand-binding IL-11Rα subunit and two molecules of the expressed cell signaling β subunit, gp130. The functions of IL-11 are that it directly stimulates the proliferation of hematopoietic stem cells and megakaryocyte progenitor cells, and induces megakaryocyte maturation resulting in increased platelet production.