Aberrant activation of the JAK/STAT pathway plays a central role in myeloproliferative neoplasms (MPNs), a group of heterogeneous diseases including polycythemia vera (PV), essential thrombocythemia (ET), and chronic idiopathic myelofibrosis (MF) [1, 2]. The gene discussed is SOAT1; the disease is acquired polycythemia vera.