DDIT3 and myelodysplastic syndrome: To determine the role of its upregulation in HSCs from MDS patients, DDIT3 was overexpressed in HSCs from healthy donors (YH_18, YH_19) (validation of the overexpression system at protein level by immunofluorescence in primary cells, and by immunoblot in cell lines can be found in figures Fig. S3c, d; and HSCs gating strategy in Fig. S1a), and sorted transduced cells were analyzed by MARS-seq after 2 days in culture in the absence of differentiation stimuli (Fig. 3a).