CD34 and myelodysplastic syndrome: To assess the effect of anti-CCRL2 ADC on healthy hematopoietic cells, CD34 + cells sorted from bone marrows of 3 independent healthy donors (Supplementary Table 2) were treated with 100 ng/ml conjugated IgG2a or anti-CCRL2 ADC, which is a substantially higher dose compared to the doses selected to treat primary MDS/AML samples for 5 days.