It is worth noting that all four overlapping DMRs, including DMRs within BCL9L and NOTCH1, were hypermethylated in high-maturity memory B cells and hypomethylated when comparing SF3B1mut vs. SF3B1WT CLL, suggesting an association of SF3B1 mutations with less mature B cell developmental stages in CLL. This evidence concerns the gene BCL9L and B-cell chronic lymphocytic leukemia.