In the discovery cohort, oncostatin M (OSM) and hepatocyte growth factor (HGF) were increased in MS, whereas fibroblast growth factor 21 (FGF‐21), fibroblast growth factor 23 (FGF‐23), and cystatin D (CST5/CST‐D) were decreased.9 Here, FGF21 is linked to myeloid sarcoma.