In this issue of Leukemia Research, Drexler and MacLeod raise questions about the origins of cell lines used in the study of Waldenström's macroglobulinemia and suggest caution in the use of these cell lines as models of this disease [Drexler HG, Macleod RAF. Malignant hematopoietic cell lines: in vitro models for the studies of Waldenström's macroglobulinemia. Leuk Res 2008].