(A) Mammary glands of 12-week-old NRL-PRL females did not exhibit marked morphological differences and did not express different levels of ER and PR from wild-type (WT) age-matched females.
(B) Histology of tumors sequenced and characterized in the discovery set and representative adjacent glands.
ER, estrogen receptor alpha; PR, progesterone receptor. Scale bars, 50 μm.