Histologic and immunohistochemical analyses of paraffin-embedded subcutaneous and lung tumors. Tumor sections (5 μ) were either stained with hematoxylin and eosin (H&E) or treated with antibody as described in “Materials and methods.” (A) H&E-stained subcutaneous tumor; (B-D) immunohistochemical detection of TFPI-2 (arrows) in subcutaneous tumors; (E-F) immunohistochemical detection of BrdU-positive cells (arrowheads) in subcutaneous tumors; (G-H) TUNEL staining for apoptotic cells (arrowheads) in subcutaneous tumors; (I-J) anti-TFPI-2 IgG immunohistochemistry of metastatic lung tumors. Boxed area in I is magnified an additional 2.5-fold in panel J. PC indicates peripheral cells (D,F,H). CC indicates core cells (C,E,G). Original magnifications: × 250 (A-B); × 1000 (I); × 2500 (C-H,J).