TFRC and neoplasm: By conducting a colony-forming unit (c.f.u.)assay27, we found that seeding normal MEPs in 10% collagen medium mainly formed CD41+CD71+ megakaryocyte/erythrocyte, CD71+ erythroid-only and CD41+ megakaryocyte-only colonies (Fig. 1e), whereas MEPs from tumor-bearing mice formed more megakaryocyte-only but less erythrocyte-only colonies (Fig. 1f and Extended Data Fig. 1k).