Cahill et al. [27] showed that high levels of DNA methylation in the CLLU1 gene were present in immunoglobulin heavy chain- (IGHV-) mutated (IGHV-M) CLL and in normal B cells of IGHV-unmutated (IGHV-UM) patients. This evidence concerns the gene CLLU1 and B-cell chronic lymphocytic leukemia.