TOX3 is expressed in mouse and human mammary epithelium. A. Gating strategy used to sort mouse mammary epithelial cell populations is shown. Contour plot on the right is gated on the luminal epithelial population as shown. B. qRT-PCR for mouse Tox3 in the indicated sorted cell populations. Data are expressed as mean ± SD of three independent sorts. C. Immunohistochemical staining of TOX3 in reduction mammoplasty samples showing areas of high and low TOX3 protein expression within an individual (magnification, 40X). D. Immunohistochemical staining of serial sections with antibodies specific for TOX3, ER, and PR (magnification 20X). E. Immunohistochemical staining of serial sections for TOX3 and FOXA1 at indicated magnification. Examples of FOXA1+ and FOXA1− nuclei are indicated by red and green arrows, respectively.