MYC and B-cell non-Hodgkin lymphoma: Among the tumors that formed in the Mb1-Cre Bim-deleted Eμ-Myc mice, there were higher proportions of surface IgM-negative precursor B cell lymphomas compared to the Mb1-Cre Eμ-Myc control mice (Figure 4B), although this difference was statistically not significant.