Despite cell counts meeting the criteria for “effective”, the investigator judged the response to be “not effective” in this participant, since these counts might have been related to administration of romiplostim, a thrombopoietin receptor-agonist that can stimulate erythrocyte, neutrophil, and platelet production in patients with aplastic anemia [14]. The gene discussed is MPL; the disease is idiopathic aplastic anemia.