CCL1 expression in human tissues. Immunohistochemical staining for podoplanin (lymphatic vessels) and for human CCL1 on serial sections of normal human skin (A and B), melanoma in the skin (C–F), and lymph nodes with melanoma metastases (G–J). (E and F) Higher magnification of the boxed area in C and D. (G–J) Serial sections of human lymph node with melanoma metastases stained with H&E (G) or immunostained for podoplanin (H) or CCL1 (I and J). (H) Podoplanin identifies lymphatic vessels of the SCS (arrows) and lymphatics associated with melanoma metastases in the cortex. (I) CCL1 staining (red, arrows) on a serial section. (J) Higher magnification of the boxed area in I. Images are representative of at least 10 skin samples, 14 primary tumors, and 8 lymph node samples. Arrows, lymphatic vessels; t, tumor; ep, epidermis; c, capsule. Bars: (A–F, H, and I) 100 µm; (G) 250 µm; (J) 25 µm.