MPN: myeloproliferative neoplasm(s); CML: chronic myeloid leukemia; PMF: primary myelofibrosis; PV: polycythemia vera; ET: essential thrombocythemia; PDGFRA/B: platelet-derived growth factor receptor alpha/beta; FGFR1: fibroblast growth factor receptor 1; PCM1-JAK2: pericentriolar material 1, Janus kinase 2; AML: acute myeloid leukemia; CMML: chronic myelomonocytic leukemia. The gene discussed is FGFR1; the disease is acquired polycythemia vera.