Pkn2 expression in tumor cells was compared to that seen in normal bone marrow cells, in sorted IgM+ cells from a spleen of a healthy C57BL6 mouse, to the mouse pre-B cell lymphoma cell line (70Z/3), and to the mouse mature B cell lymphoma cell line (CH12). The gene discussed is CD40LG; the disease is B-cell non-Hodgkin lymphoma.