Consistent with the presence of more immature T cells in the VC Phf6 + JAK3M511I populations, extreme limiting dilution assay demonstrated a marked increase in LICs activity in Phf6 KO T-ALL cells when compared with Phf6 WT T-ALL cells, indicating that loss of Phf6 promoted LICs self-renewal and proliferation (Figs. 4H–J and S2D). This evidence concerns the gene PHF6 and acute lymphoblastic leukemia.