Fig. 1

Zinc accumulation reflects breast cancer subtype in human tumors. Representative images of sections (5 μm) of non-malignant breast tissue, Luminal (ER+/PR+/HER2+) or Basal (ER-/PR-/HER2-) tumors (n = 2 women/sub/type) stained with hematoxylin and eosin (H & E; 5 or 10× magnification). Malignant regions (noted in box) were visualized by light microscopy (phase; 20× magnification), identified in serial sections (20 μm), and then analyzed by X-ray fluorescence microscopy. The corresponding element (phosphorus, zinc, calcium) is shown above each image. The rainbow color scale reflects the signal intensity measured as micrograms per square centimeter in each pixel, with darker pixels (purple, blue) representing areas of low concentration and brighter pixels (yellow, red) representing areas of high concentration. A scale bar (100 μm) is shown below the phase contrast images