To identify the transcriptional alterations characterizing hematopoietic progenitors harboring del(5q), we initially performed scRNA-seq of CD34+ cells of four newly diagnosed patients with del(5q) MDS (Patient_1-4), and three age-matched healthy donors (Healthy_1-3) using the 10X Genomics technology (Fig. 1A) (gating strategy can be found in Supplementary Fig. 1). Here, CD34 is linked to myelodysplastic syndrome.