The FXB15 enhancer had a reduced activity as inferred from the loss of ATAC signal in CLL, potentially causing downregulation of NFKB2. Based on these observations, we propose that rewiring between enhancers and their target promoters might be one mechanism that leads to deregulated gene expression in CLL. This evidence concerns the gene NFKB2 and B-cell chronic lymphocytic leukemia.