In PMF, risk factors for leukemic transformation include IDH1, IDH2, SRSF2 or ASXL1 mutation, high risk/unfavorable karyotype, circulating blasts ≥3%, age >70 years, moderate/severe anemia, and thrombocytopenia [6–10]; a risk model based on these risk factors distinguished a high-risk group with BP-MPN incidence of 57%, intermediate-risk 17% and low-risk 8% [10]. The gene discussed is IDH2; the disease is anemia (phenotype).