Loss of Bif-1 promotes Myc-driven lymphoma development. (A) Kaplan-Meier tumor-free survival of Eμ-Myc/Bif-1^+/+ (n = 52; median onset, 107 days), Eμ-Myc/Bif-1^+/− (n = 53; median onset, 75 days), and Eμ-Myc/Bif-1^−/− (n = 9; median onset, 65 days) mice is shown. Statistical significance was determined using a log-rank test. (B) Bif-1 haploinsufficiency enhances the frequency of thymic lymphoma in Eμ-Myc–transgenic mice. Gross images of typical lymphomatous Eμ-Myc/Bif-1^+/+ and Eμ-Myc/Bif-1^+/− mice with thymic lymphoma are shown. The lymph nodes and thymus are outlined by yellow circles and a white circle/arrow, respectively. Statistical significance was determined using a Fisher exact test. (C) The weights of spleens from all of the mice used in this figure were measured at the onset of lymphoma and are shown as a box plot. The lines, boxes, and error bars represent median values, 25-75 percentiles, and the 10-90 percentiles, respectively. (D-E) Allelic loss of Bif-1 suppresses lung perivascular tumor formation in Eμ-Myc–transgenic mice. The lungs (D) and livers (data not shown) from lymphomatous Eμ-Myc/Bif-1^+/+ (n = 34; ii), Eμ-Myc/Bif-1^+/− (n = 38; iii), Eμ-Myc/Bif-1^−/− (n = 8; iv), and control Bif-1^+/+ mice (i) were stained with H&E. The degree of lymphoblast infiltration to pulmonary alveolar septa (D) or hepatic sinusoids (E) and perivascular interstitial stroma expanded by lymphoblasts (D-E) were scored as follows: 0 = normal; 1 = < 5%; 2 = 6%-15%; 3 = 16%-40%; and 4 = > 40%. The lines represent median values. Statistical significance was determined using a 2-way ANOVA followed by a Scheffe posthoc test. *P < .05.