RANTES expression and level of apoptosis in situ in shikonin and mRANTES cDNA transgene-treated skin tissues. Immunohistochemistry was performed at the indicated time points from vehicle-treated, shikonin-treated, empty pVector-transfected or pRANTES cDNA-transfected skin. (a) mRANTES protein expression; brownish staining (yellow arrows) was revealed by immunoperoxidase staining using avidin-biotin-peroxidase complexes counterstained with hematoxylin. (b) In situ apoptosis detection showing apoptotic cells stained in brownish color (black arrows) was observed in the epidermis. All test skin tissue sections were counterstained with hematoxylin. Similar results were observed in skin biopsies from three different mice, and a representative histological result is shown. Scale bar: 200 μm.