JAK2 and myelofibrosis: Specifically, when the Jak2 inhibitor Ruxolitinib/Jakafi was administered to myelofibrosis patients with the intent of reducing blood transfusion dependency via the targeted suppression of mutant granulocyte/macrophage progenitors, it was reported that the drug was more likely to cause anemia and thrombocytopenia, than to correct them [18].