KDM2B is required for the maintenance of T-ALL. (A) In vitro proliferation of human T-ALL cell lines after the knockdown of KDM2B. mCherry tagged sh-KDM2B or control sh-SCR viruses were transduced into human T-ALL cell lines with (Jurkat) and without (TALL-1) NOTCH1 activation. mCherry positive cells were isolated by cell sorting. Data are shown as the mean ± SEM of triplicate cultures. (B) In vitro proliferation of mouse ΔCxxC T-ALL cells after the overexpression of KDM2B. GFP-tagged 3xFLAG-Kdm2b or control viruses were transduced into ΔCxxC T-ALL cells immortalized from primary ΔCxxC T-ALL cells. GFP⁺ cells were isolated by cell sorting. Data are presented as the mean ± SEM of triplicate cultures. (C) Kaplan-Meier survival curves of the sublethally irradiated recipient mice infused with ΔCxxC T-ALL cells with or without KDM2B add-back. A total of 1 or 5 × 10⁶ cells were transplanted into each recipient. (D) Scatter diagram showing RNA-seq data. Signal levels of RefSeq genes (FPKM+1 in log2) in control and KDM2B knockdown human T-ALL cell lines are plotted. Representative direct target genes of NOTCH1 are shown as red dots. (E) Scatter diagram of the H2AK119ub1 and KDM2B enrichment (ChIP/input, RPKM+0.1 in log2) in human T-ALL cells. (F) Summary of KDM2B binding and H2AK119ub1 levels detected by the ChIP-seq analysis. The fold enrichment values of KDM2B and H2AK119ub1 ChIP signals were calculated against the input signals (ChIP/input, RPKM+0.1) around the TSS (±2 kb) of RefSeq genes in Jurkat and TALL-1 cells. Left, all RefSeq genes; right, NOTCH1 target genes in DP T-ALL cells defined by the previous study.³²  *P < .05; **P < .01; ***P < .001 by Student t test.