Imiquimod enhances erythroid output of human primary cells in vitro. (A-D) Primary cells obtained from BMs of anemic patients detailed in the supplemental Table 1 (n = 4) underwent fluorescence-activated cell sorting into different populations. Sort purity was verified as greater than 95% for all conditions. CFU-assays were performed in triplicate in Methocult without serum. Colonies were scored at 12 days, and output is shown as percentages of cells input. HSPCs (A), CMPs (B), MEPs (C), and granulocyte macrophage progenitors (GMPs) (D). (E-G) Individual patient plots show the change in colony output associated with imiquimod for MEPs (E-H) and CMPs (I-J). BFUE, burst-forming unit erythroid; GEMM, granulocyte, erythrocyte, macrophage, and megakaryocyte; GM/G, granulocyte-macrophage/granulocyte; M, macrophage; AML_PR, acute myeloid leukemia in partial remission; MDS-MD, myelodysplastic syndrome with multilineage dysplasia; DLBCL, diffuse large B-cell lymphoma.