GSTM1 and anemia (phenotype): These processes disrupt the physiologic medullary erythropoietic environment, leading to decreased erythropoiesis, progressive bone marrow failure and anemia (hemoglobin [Hb] levels < 10 g/dL); anemia is one of the three cardinal features of MF besides splenomegaly and constitutional symptoms (night sweats, low-grade fevers, itching, bone pain, fatigue, unintentional weight loss, and cachexia) [4].