Fig. 1

Representative immunohistochemical stainings of FoxP3+ Regulatory T cells (Tregs). Immunohistochemical stainings of FoxP3 in benign (a) and dysplastic nevi (b), in situ melanoma (c), superficial (Breslow’s depth < 1 mm, d) and deep (Breslow’s depth > 4 mm, e) melanomas and lymph node metastasis (f). The dashed line in a and b marks the epidermis in benign and dysplastic nevi, respectively, and the dashed line in c stands for the tumor-stroma borderline in in situ melanoma. In in situ, thin and deep melanomas and LNMs (c-f), FoxP3+ Tregs are also found inside the tumor cell nests. The asterisks in c-f indicates the stromal compartment of the tumor. Scale bar is 50 μm in a for a-c (× 200 magnification) and 100 μm in d for d-f (×100 magnification)