Figure 7.

Impact of Ept loci on E2-induced mammary cancer. Female rats of each strain were treated with E2, released from sc SILASTIC brand implants, beginning at 9 wk of age. Control rats received empty implants. The rats were euthanized 28 wk later or as necessitated due to treatment-related morbidity. Each data point represents the time at which an animal in the population at risk exhibited the first palpable mammary cancer. Mammary cancer did not develop in untreated, ovary intact, female rats during the course of this experiment. A, Data from the Ept1 and Ept2 congenic strains are illustrated relative to data from the ACI and COP strains. B, Data from the Ept6 and Ept9 congenic strains are illustrated relative to data from the ACI and COP strains.