Central role of (aberrant) JAK/STAT signaling in MF. (A) Simplified scheme of JAK/STAT signaling. (B) Alterations found leading to increased transcriptional activity of gene promoters with STAT binding sites. Some features are shared with Sz (eg, malignant inflammation and JAK mutations), whereas others are typical for MF (loss of SOCS1 and upregulation of miR-155).