Allelic disruption of Beclin1 suppresses spontaneous renal tumorigenesis in Tsc2 heterozygous mice. (A) The kidney with the most severe lesions from each genotype is shown; arrows indicate cystadenomas. (B) Macroscopic tumor scores from WT (wt), Tsc2+/− (T2+/−), Beclin1+/− (B1+/−), and Tsc2+/−Beclin1+/− (T2+/−B1+/−) littermates (n = 8 kidneys per genotype). No tumors were observed in WT or Beclin1+/− mice. *P < 0.05. (C) Representative H&E-stained lesions. N, normal kidney. T, cystadenomas. (Original magnification, 20×.) (D) Microscopic tumor scores. *P < 0.05.