Eμ-Myc mice typically develop pre B cell lymphomas (149) but later stages also IgG+ tumors and Λ-Myc mice succumb to more mature B cell lymphoma (150) that resemble GC derived since they are B220+, IgD-, CD38lo and GL7+, but lack CD95 (Moroy et al., unpublished). This evidence concerns the gene FAS and B-cell non-Hodgkin lymphoma.