Methylation analysis of the entire panel of leukemia and lymphoma cell lines, determined by pyrosequencing, revealed that in myeloid derived cancer cell lines the WT1 CpG island promoter is unmethylated, except for the HL-60 cell line that was completely hypermethylated, whereas the AWT1 CpG island promoter was methylated in all cell lines evaluated. This evidence concerns the gene WT1 and lymphoma.