Figure 2: Representative mammary gland whole mounts without and with tamoxifen treatment in six-month and one-year old CERM, CERM/ D1, D1 and WT mice. Representative whole mount images of six-month and one-year old CERM, CERM/D1, D1 and WT mice treated with tamoxifen for two months demonstrating uniform ductal regression in all genotypes when treated at four months of age and presence of multiple HANs in CERM and CERM/D1 mice when treated at ten months of age (arrows and insets).