More recently, Wobus et al. [286] have demonstrated that adult bone marrow MSCs from human MDS patients treated with luspatercept, a novel recombinant Fc fusion protein containing a modified type IIB activin receptor, increased colony forming cell (CFC) potential in vitro of healthy but not MDS HSPCs, while pretreating MSCs from MDS patients with luspatercept restored the CFC potential of HSPCs in co-culture and increased both their CXCL12 secretion and HSPC homing in a surrogate zebrafish model. The gene discussed is ACVR2B; the disease is myelodysplastic syndrome.