Eltrombopag (EPAG), an oral thrombopoietin receptor agonist (TPO-RA) initially developed for chronic immune thrombocytopenia, was first proven by the National Institutes of Health (NIH) to be effective in severe aplastic anemia (SAA) patients refractory to IST (7), presuming its efficacy in stimulating residual HSPCs. The gene discussed is MPL; the disease is idiopathic aplastic anemia.