1. 10 0 1 2 3 4 0 1 2 3 4 59% Ter119 CD71 10 0 1 2 3 4 0 1 2 3 4 13% 10 0 1 2 3 4 0 1 2 3 4 1.5% +/+ki/ki 10 0 1 2 3 4 0 20 40 60 80 100 2.71 10 0 1 2 3 4 0 20 40 60 80 100 56.2 10 0 1 2 3 4 0 20 40 60 80 100 15.2 Thiazole orange % max 10 0 1 2 3 4 0 1 2 3 4 1.6% 10 0 1 2 3 4 0 20 40 60 80 100 3.36 A B PBMC Figure S8 1 (HCT: 43.3)2 (HCT: 40.8)3 (HCT: 20.8)(HCT: 49.7)

2. 010 3 4 5 0 3 4 5 0.33 6.87 27.1 24 010 3 4 5 0 3 4 5 0.015 0.42 5.61 41.4 010 3 4 5 0 3 4 5 3.14 5.76 8.18 2.34 010 3 4 5 0 3 4 5 4.65 8.56 12 4.03 010 3 4 5 0 3 4 5 0.46 13.7 15.3 31 010 3 4 5 0 3 4 5 1.39 13.6 12.9 9.33 010 3 4 5 0 100 200 300 400 2.43 010 3 4 5 0 30 60 90 120 21.6 BM spleen Ter119 CD71 C n.d. 010 3 4 5 0 50 100 150 200 9.89 7-AAD % max D +/+ ki/ki Figure S8

3. Figure S9 10 0 10 1 10 2 10 3 10 4 10 0 10 1 10 2 10 3 10 4 11.674.3 2.6211.5 BasE ProE Ter119 CD71 +/+ki/ki A 22.5 47.9 3.71 25.8 BasE ProE 10 0 10 1 10 2 10 3 10 4 10 0 10 1 10 2 10 3 10 4 02004006008001000 0 50 100 150 200 24.4 74.6 02004006008001000 0 20 40 60 48.3 51 02004006008001000 0 10 20 30 96.2 3.36 02004006008001000 0 5 10 15 20 68.4 31 BasE ProE PI # Cells B C 0 5 10 15 20 25 30 35 +/+ki/+ki/ki %CD71+, 7AAD+ cells 0 5 10 15 20 25 30 35 40 45 +/+ki/+ki/ki %CD71+, AnnexinV+, 7AAD- cells

4. +/+ +/ki ki/ki spleenBM spleen BM +/++/kiki/ki pi staining cell number Figure S10 +/+ +/ki ki/ki 0 20 40 60 80 100 2N4N8N16N32N+ percentage *

5. Figure S11 bone marrow basophilic erythroblasts GATA-1/FOG-1 activatedGATA-1/FOG-1 repressed 0 5 10 15 20 25 Kit MycLyl1 GATA-2 fold change * +/+ ki/ki ** +/+ ki/ki