AR expression and nuclear localization in TNBC patient samples and cell lines. A, representative immunohistochemistry (IHC) of AR protein expression (brown) in TNBC patient samples. Photomicrographs represent a 400× magnification. B, Western blotting for AR expression in a panel of TNBC cell lines representing LAR, basal-like 2 (BL2), MSL, and mesenchymal-like (ML; ref. 14) subtypes of TNBC. The prostate cancer cell line LNCaP is shown as a positive control for AR. C, nuclear–cytoplasmic fractionation of TNBC cell lines grown in 5% charcoal-stripped serum for 48 hours and following a 3-hour treatment with vehicle control (Veh), enzalutamide (ENZ), and/or DHT. Topoisomerase I (TOPO1) is a loading control for the nuclear fraction and α-TUBULIN is a loading control for the cytosolic fraction.