Integrating RBPJ-occupied genes in HG3 cells, RNA-Seq of USP28WT/KO cells and gene expression from del(11q) CLL patients, we identified 15 NOTCH1 target genes specifically dysregulated by deletion of USP28 and del(11q) potentially influencing CLL pathogenesis. Here, RBPJ is linked to B-cell chronic lymphocytic leukemia.