Initially, prior to the appearance of neoplasms, Foxa2/Pten-deficient but histologically normal glands retained ERα and PR, whereas invasive cancers in animals at 12 months of age showed ERα/PR loss (Supplemental Figure 4), similar to the loss of ERα/PR in human ECs (Figure 1, E and G). This evidence concerns the gene ESR1 and neoplasm.