IL11 and plasmacytoma: The interleukin‐11 (IL‐11) is a member of the interleukin‐6 cytokine family due to their common feature of using the type I cytokine receptor glycoprotein 130 as the β‐subunit in their multimeric receptor complexes.15 In 1990, IL‐11 was identified from the supernatants of immortalized primate bone marrow stromal cells with the activity of plasmacytoma stimulatory.16, 17 During normal homeostasis, IL‐11 expression levels are usually low and therefore difficult to detect.