Tumorigenesis in mice deficient for p37Ing1. A, Kaplan-Meier survival curves of cohorts of Wt, p37Ing1-heterozygous, or p37Ing1-null mice. Mice that were either moribund or reached 22 mo of age were sacrificed for necropsy and fixed in 10% phosphate-buffered formalin. The rate of tumor incidence between Wt and either p37Ing1-heterozygous or p37Ing1-null mice is statistically significant (P < 0.005 or P < 0.05, respectively). B, tumors arising in mice were paraffin embedded and H&E stained for pathologic analysis. Tumor sections were also stained with either B220 or CD3 antibodies to determine tissue of tumor origin.