Fig. 2. Immunohistochemical staining of necrotic/hypoxic melanoma metastases for the activated kinase JNK/SAPK. A and B, immunohistochemical staining of phospho-JNK/SAPK in a melanoma metastasis. Arrowheads indicate the demarcation line of positively stained tumor cells adjacent to a necrotic tumor area depicted as N. B, higher power view of A. C and D, immunohistochemical staining of a serial section of the metastasis from A and B for HIF-1 shows positive staining in the same tumor area. D, higher power view of C. E and F, immunohistochemical detection of blood vessels (anti-CD34 staining) in the same metastasis at a distance far from the necrotic area. F, higher power view of E. Original magnification in A, C, and E, x200; original magnification in B, D, and F, x400. Scale bars in A, C, and E = 50 µm; scale bars in B, D, and F = 25 µm. N, necrotic area.