T-bet acts as a silencing TF in CLL cells. (A-B) Differential chromatin accessibility in (A) Tbx21^–/– vs Tbx21^+/+ TCL1 cells analyzed by scATAC-seq and (B) TBX21^low vs TBX21^high CLL cells analyzed by ATAC-seq (FDR 0.05). The numbers of up- and downregulated peaks are indicated. (C) Motif enrichment analysis of the ATAC-seq data was performed individually for U-CLL, M-CLL, and TCL1 cells. Commonly enriched motifs are displayed.