CXCR4 and B-cell chronic lymphocytic leukemia: In a study aimed at dissecting CRCs in primary CLL and normal B cells (NBCs), SEs with exceptionally high H3K27ac marks (42% of all H3K27ac marks globally) were discovered in proximity to genes involved in CLL pathobiology, including CXCR4, CD74, PAX5, CD5, KRAS and BCL2 [41].