CD34 and plasma cell myeloma: In addition to the intrinsic deficits in the erythropoiesis of CD34+ HSPCs with downregulated GATA1 expression in a myeloma bone marrow microenvironment, we found that the bone marrow plasma cells of myeloma patients further suppressed the BFU-E formation of CD34+ cells both from myeloma patients and healthy donors (Fig. 6A).