FLT3 and myeloproliferative neoplasm: Interestingly, a recent study revealed that circulating MSC-derived OSMR was the strongest negative predictor in newly diagnosed AML patients, whereas OSMRhigh patients had upregulated IL-6 and OSM according to differential protein expression analysis of PB, as well as enrichment of IL-6/JAK/STAT and the inflammatory response in gene set enrichment analysis.11 We therefore propose OSM as a therapeutic target for MPN patients and potentially for those harboring STAT5-activating oncogenes such as FLT3-ITD.