CD34 and acute lymphoblastic leukemia: To assess the impact of PHF6 loss on the differentiation potential of human HPCs, we first optimized stable PHF6 knockdown in Jurkat T-ALL cells using lentiviral gene transfer (Supplementary Figure 1a) and this confirmed strong PHF6 downregulation both at the mRNA (left) and protein level (right) which was also observed at the mRNA level in cord blood (CB)-derived CD34+ HPCs (Supplementary Figure 1b).