MPL and plasma cell myeloma: We next investigated whether eltrombopag affects the proliferative capacity of human myeloma cells via c-mpl-independent pathways, either alone or in combination with other hematopoietic growth factors such as granulocyte colony-stimulating factor (G-CSF) and erythropoietin (EPO), which are often used as supportive therapy to treat cytopenias associated with anti-myeloma therapy.