IL11 and Bone marrow hypocellularity: Recombinant IL-11 has been used to diminish activated Th1 cells,19 and its thrombopoietic activity was reported in patients with bone marrow failure caused by myelodysplastic syndromes, graft failure, chemotherapy and AA.20, 21 The effects we observed in the present study seem to be mediated by an autonomous signaling pathway in HSCs.