The presence of HL within SLL/CLL was also identified by cytomorphologic examination and identification of characteristic large Reed-Sternberg cells with a CD15/LeuM1- and CD30-positive immunophenotype by immunohistochemistry, a polymorphous background and a neoplastic B-cell population of SLL/CLL [Figure 4]. This evidence concerns the gene TNFRSF8 and B-cell chronic lymphocytic leukemia.