Electrophoretic mobility shift assay confirmed that STAT3 bound to the miR-155 promoter in CLL cells, and chromatin immunoprecipitation and luciferase assay confirmed that STAT3 bound to the 700–709 bp but not the 615–624 bp putative STAT3 binding site in CLL cells. This evidence concerns the gene STAT3 and B-cell chronic lymphocytic leukemia.