Dysregulated IRF expression in patients with ductal carcinoma. A. Normal and ADH breast tissue specimens were stained by IF or IHC. Antibodies recognizing IRF5 (FITC), IRF1 (Cy3) and DAPI for the nucleus were used for IF. For IHC, tissues were stained for IRF1 with DAB (brownish-red), IRF5 with BAP (blue), and nucleus with Fast Red mounting buffer. B. Same as in (A), except tissue samples from patients with ADH were stained by IF with IRF5 (FITC) and CK14 (Cy3) in order to confirm expression of IRF5 in myoepithelial cells. C. Same as in (A), except tissues from patients with DCIS and IDC were examined. Representative pictures of low grade and high grade DCIS are shown illustrating distinct differences between IRF1 and IRF5 expression. Images were taken on a Zeiss Axiovert Apotome microscope at 20 × or 40 × magnification. Scale bars are 50 μm.