FIG. 3.

Kaplan-Meier plots of incidence of mammary tumors and thymic lymphomas induced by wild-type and mutant MMTV proviruses. Female mice were caged to maintain continuous breeding and lactation. Mice that died from nontumor causes (e.g., birthing problems) before the average latency of tumor induction were excluded from the study. (A) Development of mammary tumors. Numbers in parentheses indicate the numbers of animals with tumors/total numbers of injected females. The circles indicate one or more animals that died without any detectable tumors. (B) Development of thymic lymphomas. Numbers in parentheses indicate numbers of animals with tumors/total numbers of injected males and females. One mouse injected with HYB-MTVStuE developed both a mammary tumor and a thymic lymphoma after 11 months of latency.